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Thread: Hot tub arrived, water chemistry questions

  1. Back To Top    #1

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    Hot tub arrived, water chemistry questions

    Wahoo! The new hot tub came on the 23rd and we filled with a mix of hot/cold tap water so we could jump in at 11:30 that nite Love it!!!

    I have to update my signature but it's a Jacuzzi J-385 500 gallon. The store tested our water ahead of time so they could tell us what to put in it. We're on a well. Initial readings from tap sample (no softener in the system) were:

    pH: 7.6
    Hardness (I assume this is calcium?): 200ppm
    Alkalinity: 70ppm
    Copper: 0ppm
    Iron: 0ppm

    For start up here's what they had us do:
    1.) Fill and turn on the jets, pour in a full bottle of of Leisure Time Metal Gone and wait 4 hours (the guy said even tho iron and copper were 0, they don't test for other metals so this is more just to ensure other metals are out).
    2.) After 4 hours - add 3oz of Leisure Time Alkalinity Increaser to get it to the desired 80 - 120ppm range
    3.) Put the ProClear cartridge inside the circ pump filter (I'm assuming this is like a Nature2 cartridge under a different name?)
    4.) After an hour add 2oz of Leisure Time Spa 56 (sounds like this is a Chlorine product that works with the ProClear UV light so we don't need as much as we would without the bulb?)

    Then they said after we get out after each soak, add one tablespoon of Leisure time Replenish per person and let the jets run through a 20 minute cycle. Is this just some sort of oxidizer/chlorine maintainer? He also said if it's just the two of us, we may not need to do this EVERY time if we use it a lot, every other time or cut the dose in half.

    Told us to use the test strips weekly to check and balance water (I plan to switch to the Taylor 2006 kit given what I've read on strips) and also add 2oz of the Spa 56.

    Does this all sound ok? Is there anything else I should know? This is all new to me. Tuesday and Wednesday soaks were fine, SLIGHT chlorine smell but not as strong as I expected and they told us it shouldn't smell like a lot of chlorine or something is off. My husband got me some Spazazz vanilla crystals we threw in the one nite (said we could put 1tbsp / 100 gallons but we cut that down a bit) and we have a very faint waxy type ring at the water level now on the side closest to wear he tossed them in from so I'm wondering if it's those or just buildup from shampoo in our hair and stuff (my hair is long enough to get wet a bit but too short to tie up, PITA). Also - we see a bit of foam when we're in there soaking and the jets are on but it's like the total of a palm full and not high and frothy, just not air bubble type foam so we just scoop it out. We don't wear body creams so I'm thinking it's not that tho what do I know. Also saw a scum bug thing they say can help with that.

    Just went and used a test strip since the K-2006 hasn't arrived yet and when we lifted the cover there was a fair amount of chlorine smell (not like a pool but stronger than the past few days, tho this is also the first time we have a "spa blanket" on it under the cover so maybe that adds to it. My hand doesn't smell overly strong of chlorine from being dipped in the water.

    Anyway, FCl read nothing. Didn't even register a color.
    Alk was right about 120 based on the color (ok range according to the strip)
    Ph was right between 7.2 and 7.8 so good there
    Total Hardness (Calcium?) was about 100, so a bit low I think. Odd since we're on a well and when the stored tested our tap sample prior to filling the computer read it as 200. Wondering if there's some relationship between FCl and Hardness I need to investigate and read up on.

    Thanks in advance for any feedback.

  2. Back To Top    #2

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    Re: Hot tub arrived, water chemistry questions

    Well, you really didn't want to get your TA up to the 80-120 ppm range if you planned on using the Dichlor-then-bleach method or any other method that avoided CYA or CH buildup. Leisure Time Spa 56 is Dichlor. The UV won't help very much unless you kept your chlorine level high during a soak in which case the UV might help control chloramines somewhat so reduce their smell. Otherwise, the UV will just use up chlorine faster (ozone does that as well though in heavy bather load spas it oxidizes bather waste). Leisure Time Replenish is a combination of Dichlor and non-chlorine shock (MPS). By weight it's around 15% Dichlor and 31% MPS (72% of the Oxone triple salt -- they incorrectly say on the label this is potassium monopersulfate but only part of it is that chemical) and 13% Other ingredients (possibly an unspecified clarifier).

    You need to decide how you are going to manage your spa. At this point, you've been following what the spa store tells you to do. You're on your own in that case. If you want to follow TFP practices, then read the Pool School article Using Chlorine in Your Spa. The ProClear cartridge is 0.92% metallic silver (from silver nitrate) so competes with Nature2. You need to decide whether you want to have a chlorine spa such as using the Dichlor-then-bleach method described in the Pool School article or whether you want to try mostly non-chlorine where you primarily depend on the silver ions and MPS for disinfection and most oxidation. Just note that unlike Nature2, ProClear did not go through EPA approval. When using primarily MPS, one usually needs to use chlorine every week or so to keep the water clear since MPS doesn't oxidize all the bather waste.

    With either technique (chlorine or MPS) the rough rule-of-thumb is that every person-hour of soaking in a hot (104F) spa requires around 3-1/2 teaspoons of Dichlor or 3-1/2 fluid ounces of 8.25% bleach or 7 teaspoons of 43% MPS non-chlorine shock. The real rule is to add whatever amount is needed after a soak so that you still have a measurable residual for the start of your next soak. Usually people start their soak with around 1-2 ppm FC to minimize odor and then add chlorine or MPS right after their soak.

    The Dichlor-then-bleach method is the least expensive and easiest to measure method. Does your spa have an ozonator? How often do you plan to use the spa? The main downside with chlorine methods is that ozone reacts with chlorine so if you don't use the spa every day or two, then the ozonator uses up chlorine so quickly that you have to add chlorine every day or two. With no ozonator, you can probably just add chlorine once mid-week if you only soak on weekends (you might be able to shock it higher after a soak and have it last the week if the water temperature is allowed to drop, but again only if there is no ozonator). Your UV system may act somewhat like an ozonator in that it may increase chlorine demand. If you aren't soaking frequently, you may consider disconnecting it (or may just do that anyway regardless).

    You refer to your own testing with Total Hardness which includes magnesium since that is what test strips are mostly limited to testing. As you can tell, it's probably wrong. Once you get your K-2006 you can get the CH to 150 ppm to reduce foaming though I suspect your CH might already be that high or higher given your well water. You will want to lower your TA at some point though initially when using Dichlor you may be OK if you find your pH not rising too fast. You'll want to order the boric acid to get 50 ppm borates and can do so from DudaDiesel or The Chemistry Store. You'll add that just before switching from Dichlor to bleach and after you've gotten your TA down to 50 ppm.
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    Re: Hot tub arrived, water chemistry questions

    Quote Originally Posted by chem geek View Post
    Well, you really didn't want to get your TA up to the 80-120 ppm range if you planned on using the Dichlor-then-bleach method or any other method that avoided CYA or CH buildup. Leisure Time Spa 56 is Dichlor.
    I will have to do some reading since I don't know what the dichlor-then-bleach method is. I thought I'd just be using what they told us to use and didn't figure I'd need to add bleach (tho I know from reading here if I do, don't get the splashless kind

    I'm confused tho. There's ProClear (which is what went in the filter that the circulation pump runs through) and on that package it says it's Nature2. Looks like they just relabel it for Jacuzzi. Says manufactured by Zodiac and distributed by Jacuzzi and has the EPA numbers on it. Then the ClearRay is the UV bulb. We don't have any type of ozonator (I'm sensitive to ozone so we wanted to avoid that). And we keep the temp at 102F

    We plan to use it a lot now because it's new but I'd imagine in time that would go down to 3 or 4 nites a week, 2 people for 2 pump cycles (40 minutes total). The tub manual says that with ClearRay going, the FCl should be no less than 1ppm and without ClearRay it'd be 3-4ppm and never get in it if it's above 5ppm.

    Looks like if we're 2 people in for 40 minutes at nite, that's 1.3 person hours so 4.5tsp so by putting in 2 tablespoons as recommended by the store, we're a touch over so I'm going to measure it tonite before we get in and see what's what.

    I agree about the strips being wrong on the CH reading. When the store tested the tap sample, they read CH at 200 and it's not like that changes from the well.

    If TA is in range, why would I need to get that down? I know you mentioned it in reference to the dichlor-then-bleach method but I'm confused. If I just go with the Replenish after each soak and Spa 56 each week, then can TA stay where it is?

    Thanks for all your help and explanation!

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    Re: Hot tub arrived, water chemistry questions

    If it's really Nature2 by Zodiac then you should be OK and if you wanted to follow the low chlorine recipe which is mostly non-chlorine shock, then you would follow the instructions in the Nature2 Spa Mineral Sanitizer Owner's Manual.

    It's good that you don't have an ozonator as that will make things simpler, especially when using chlorine (ozone can be useful when using bromine to produce more bromine from a bromide bank).

    The ClearRay manual is complete bunk if it says you can keep the FC at 1 ppm with and have to be 3-4 ppm FC without. First of all, the FC alone means nothing if there is CYA in the water since the active chlorine level is related to the FC/CYA ratio. Second, the UV doesn't affect any pathogens that don't get circulated so nothing growing on surfaces nor that can be transmitted directly from person-to-person. So their having different levels of FC in the water with and without UV is completely ridiculous and in fact in violation of EPA rules. They would not be allowed to make such claims in any commercial/public pool or spa. For your purposes, you could have 1-2 ppm FC at the start of your soak (if you are using chlorine) no matter whether you have a UV system or not.

    So the pool store happened to recommend something approximately correct. Note that they implicitly assumed a soak time. Obviously someone getting in for 10 minutes isn't going to sweat as much as someone in for an hour, yet their advice would not have accounted for that at all.

    The TA is "in range" for what the pool/spa store said is OK. That does not mean it is where it needs to be depending on the method that you use. After you switch from using Dichlor which is NET ACIDIC to using bleach which is pH NEUTRAL, if you kept your TA "in range" then the pH would likely tend to rise too quickly due to carbon dioxide outgassing. TA is a measure of the over-carbonation of the water. Though the carbonates in the water act as a pH buffer to resist changes in pH from external sources, they are also a source of rising pH on their own even if you added nothing to the water. The reason is that there is more carbon dioxide in the water than in equilibrium with the air. In spas that are hot and especially when running aeration jets, this excess carbon dioxide is driven out of the water faster and when carbon dioxide leaves the water it raises the pH (with no change in TA). This is because carbon dioxide in water is in equilibrium with carbonic acid (and bicarbonate and carbonate) so removing an acid from the water raises its pH.

    To lower the TA if you go with the Dichlor-then-bleach method, you follow the procedure in the Pool School article on how to Lower Total Alkalinity. If you instead just use Replenish after each soak and Spa 56 each week, then you can keep the TA in the 80-100 range if you find that the pH is reasonably stable and in that case you don't need the borates. The MPS in Replenish is quite acidic and the Spa 56 is also net acidic when accounting for chlorine usage so they will tend to balance the pH against the carbon dioxide outgassing from the higher TA, but they will lower the TA slowly over time so you'll need to increase it on occasion with baking soda (unless you like spending more money using spa store products -- Alkalinity Up is identical to baking soda). You don't have to use Replenish and instead could use an MPS-only product with no chlorine because you've got the Nature2 silver ion system. That way you won't smell any chlorine at all during your soak. There are many non-chlorine shock brands you can buy including Leisure Time Renew, Natural Chemistry Spa Oxidizing Shock, Spa Essentials Shock Oxidizer, Rendezvous Activate, SpaGuard Spa Shock, SeaKlear Spa Balanced Shock Oxidizer, or you can save money by getting the same chemical in pool products such as GLB Oxy Brite that is closer to the 43% MPS (the spa products tend to be lower closer to 32-38%).
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    Re: Hot tub arrived, water chemistry questions

    In looking at the insert that came with the Proclear cartridge, it mentions using Nature2 test strips to read MPS so I'm wondering if I'm trying to read FCl and it's not picking up what it should be because of my test strips. Which I'd definitely want to ask the Spa place about too since they gave me all this "stuff"

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    Re: Hot tub arrived, water chemistry questions

    MPS will register as chlorine in chlorine tests including chlorine test strips and liquid test kits (OTO, DPD, FAS-DPD). If you wanted to use a TFTestkits TF-100 or Taylor K-2006 test kit, then if you wanted to measure chlorine and MPS separately then you'd also need the Taylor K-2042.

    The MPS test strips are OK to use if you plan to use primarily MPS. Though not that accurate, you really only care about having at least some decent level of MPS in the spa at all times (so in the OK range on the test strip). Some people find MPS to be irritating but most find it OK to use especially when used in conjunction with the silver ions from Nature2 (they react with the minor most irritating component in non-chlorine shock products while the MPS itself isn't as irritating).

    One more thing to note is that a new spa may have leftover greases, oils, and even biofilm from wet testing the spa so you may find that your chlorine or MPS demand is higher than expected and that the water doesn't last very long before you need a water change. I suggest that just before you do change the water that you use Ahh-Some. If you had not already gotten started with your spa, I would have suggested using this initially on a first fill and then dump/refill before using the spa.
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    Re: Hot tub arrived, water chemistry questions

    Thanks for all the great info! Really appreciate your expertise here. So given we know I'm using Nature2 (and the instructions in it are the same as what's on the link you posted) it sounds like we're actually on the right track here. Still odd tho that I'm not registering any Chlorine on my crummy test strips when we get ready to go in at nite but given what you said about the greases/oils etc maybe that's why.

    I think for now I'll stick with the Replenish until I get the hang of all this tho before I look for something that's straight MPS. So far, we haven't really had any kind of chlorine smell except that one time and that was possibly because we put the nitely post-soak dose in and closed the cover right away. I now know I should let it mix around a bit first at least with the circ pump if not a full jet cycle.

    Knowing that I'm on Nature2, does that make more sense now that the tub manual says with Clearray you can keep the FCl at no less than 1.0ppm?

    Thanks also for the tip about the Baking Soda for when I run out of the free Alkalinity Up they gave us.

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    Re: Hot tub arrived, water chemistry questions

    We were in it for about 30 minutes tonite and started with no FCl reading (from this afternoon). When we got out, we put in the store recommended 2 tbsp of Replenish and ran the pumps for 20 minutes. Checked on a test strip after that and had a reading of 2ppm. The bottle says 1oz will raise the reading in a 300 gallon tub by 2ppm. Since 2 tbs = 6 tsp = 1oz, it seems like we actually should be putting more in after we get out to get it into the 3 - 5ppm range for right after so that as it drops between uses there's still a bit in when we get in but perhaps not since we were technically low (none) to start. Tomorrow is a week since we got the tub so I'll be doing the filter rinsing and adding the Spa 56 to "shock" it so we'll see how it goes this week with maintaining levels

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    Re: Hot tub arrived, water chemistry questions

    To repeat, the Clearray UV system does NOTHING to kill any pathogens on spa surfaces. It only kills pathogens free floating in water that gets circulated through the UV system. Most pathogens need surfaces on which to grow, whether that's particulate matter in the water or spa surfaces themselves. So the UV system does not let you have any different level of chlorine (or MPS when using Nature2) which is a disinfectant in the water which kills pathogens not only in the water but on surfaces where the UV system doesn't have ANY EFFECT WHATSOEVER. If you paid a lot extra for the UV, then just consider that like buying a car and paying for undercoating or one of those other not-really-needed extras. In a commercial/public pool or spa, UV or ozone are useful to kill the protozoan oocyst Cryptosporidium parvum, but unless you have someone sick with diarrhea (with this pathogen) into your spa, you won't ever see this pathogen.

    The silver ions in the Nature2 system do have some slow-killing pathogen effect but are really there to be used in conjunction with MPS where together they kill pathogens quickly enough to pass EPA DIS/TSS-12. So when using that system, just follow the directions to make sure to maintain an MPS level at all times. As for how much to add after a soak, you want to add enough so that you still have a measurable amount for your next soak. It sounds like you need to add more. Note that the MPS level will drop after a soak since the MPS will get used up oxidizing your bather waste in the hours after your soak. It is not a good idea to make a measurement too soon after your soak since you will be in the middle of the oxidizer getting used up. You can measure 8-12 hours later to make sure there is still measurable disinfectant (chlorine or MPS/silver) and also measure just before your next soak. If it's too low, then add more so that it lasts longer.
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    Re: Hot tub arrived, water chemistry questions

    Thanks for the added info. We didn't pay "extra" for the UV (on paper anyway) and given your comments, I'll be less concerned about replacing the bulb and paying that expense.

    I'm going to go test the tub now since we're about 15 hours out from our soak and see what's what. Today has been a week so I'm due for a dose of the Spa 56 but I'm going to wait until tomorrow because we want to get our weekly maintenance to a weekend day given our schedules (i.e. filter rinse, etc).

    I'm also going to reset the 8 hour circulation cycle to start at 7pm because we don't pay for power from 7 - 10:59pm each day so I would imagine most of our soaking will be free which is nice and we can keep half of the circ pump cycle in the free time too.

    Thanks again for all your help. I'm sure I'll still have questions but this has been very helpful.

    Happy new year!

    P.S. I saw a video of the Ahh-some gel last nite. Holy heck. Definitely will give that a shot when we have to do our first water change.

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    Re: Hot tub arrived, water chemistry questions

    Got the K-2006 test kit today and tested things. Haven't done the weekly shock yet since we wanted to get on a weekend schedule so that'll happen tomorrow. Ak was 100, pH was 7.4, CH was 100 - 120'ish (so the store originally tested the tap water as 120 and we've been reading 100 with the strips so that seems like the strips were right) and FC was .46

    Since we have the Nature2, the .46ppm (23 drops at 0.2ppm / drop) I'm going to call ok for now. We'll shock tomorrow and then do the normal post-soak dosing and take a reading to see if we need to bump up the post soak amount. For now, I'm thinking it could be a bit low since it's been 10 days since it was last shocked. Is there a minimum recommended for Nature2? My ProClear insert doesn't mention it and neither does the Nature2 low chlorine instructions. I thought I read somewhere it was .5ppm so we're pretty darn close but I can't find that info now.

    Also on the CH, I think I'm going to try to bump that up to the 150 range. The increaser the store gave us calls for 1oz = 7ppm in 500 gallons so I'm going to give it 3oz and test again since I want to keep it in range but at the low end of the range.

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    Re: Hot tub arrived, water chemistry questions

    The strips generally measure Total Hardness that includes Magnesium as well as Calcium. So they were in the ballpark, but TH was probably 140 ppm or so.

    By the way, 23 drops at 0.2 ppm per drop (so using a 25 ml sample size) is 4.6 ppm, not 0.46 ppm. So you are on the high side for the amount of chlorine though when using MPS that could just be MPS you are measuring and would be OK. With the FAS-DPD test, the MPS can show up as either FC or CC depending on whether there is any actual chlorine also present. If you intend to use non-chlorine shock (MPS) and want to distinguish between chlorine and MPS, then that Taylor K-2042 kit I mentioned earlier would be needed. If you don't care about distinguishing since both provide disinfection, then just look at total chlorine, so the sum of FC and CC, and you could just add the R-0003 drops immediately for that purpose. Of course, that means you won't be able to measure real CC (again the K-2042 would be needed to distinguish that).

    Based on the Nature2 instructions of adding 1 tablespoon per 250 gallons (though that's 19.2 grams at usual MPS product density and not the 16 grams they describe) this is equivalent to around 4 ppm FC and measures as such (or as CC -- just measure the sum for MPS if you don't have the K-2042).

    As for shocking with chlorine (you don't shock with MPS -- you dose after each soak according to bather load), the Nature2 manual says to use 1.5 tablespoons of Dichlor per 250 gallons which is around 12 ppm FC "as needed" "to remedy problems which may occur when bathing loads are high, when successive MPS2 test strip reading indicate high demand, when water appears hazy or dull, when unpleasant odors or eye irritation occur, after heavy wind and rainstorms or if foam develops."

    Since your TA is higher due to the net acidic chemicals you are using (mostly MPS), be careful about bumping up the CH since you could get your saturation index too high and cause calcium carbonate scaling especially in the gas heater. At 150 ppm CH with 100 ppm TA, you'll want to make sure that your pH doesn't rise much above 7.6. With aeration jets during spa use, the pH will tend to rise. You'll have less risk at 100 ppm CH though there is somewhat less inhibition of foam at lower CH. I'm not sure what "range" you are referring to for CH, but you do not want the CH to be too high in spas because the hotter 104F water temperature is more prone to scaling. With the Dichlor-then-bleach method we have the TA lowered to 50 ppm so the CH can be higher without a problem and the pH can get higher as well, but that's not your situation where you need a higher TA due to the net acidic chemicals you are using.
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    Re: Hot tub arrived, water chemistry questions

    The strips seemed to read TH at 100 and the K-2006 measured it at 100 - 120 but given what you've said above, maybe I'll just keep it as is. We don't have foaming other than some weird bubbles that we've decided are either from my hair getting in there or the Spazazz crystals we used the one nite (since they have a bit of the same tab coloring). There's no "foam" like the white bubbles you can't see through. The range the pool store gave us was 150 - 400 for Calcium Hardness which is why they said we didn't need to add anything since they tested our tap right at the low end of that range.

    And holy heck, it's nice I can do basic math. Too many cookies!!! Thanks for the call out there.

    I only read the FC with the test kit since that's all the strips ever read (but oddly read it as 0 last time I strip checked) and I assume if I did the additional test today for CC, I'd have an even higher reading. The test kit says add the R-0003 after the FC test and then dropwise of F-0871 measures CC.

    The pool store did say with just the two of us for one or two pump cycles per nite, we may not even need to add the "Replenish" each time. Given we're at 4.6ppm, I'm thinking we don't and probably shouldn't shock it this week and not add the Replenish until that comes down a bit more. Just odd how this reads 4.6ppm with the Taylor kit and the strips read darn near zero but they're not nature2 strips so maybe that reads the Replenish/MPS (Is that really my MPS?) differently?

    So it sounds like we don't actually need to do anything for weekly maintenance tomorrow right? Would you just leave the Calcium level alone? pH has been stable when I read with the strips. I'm wondering tho if I should get some Nature2 strips for midweek testing and save the drops for weekend testing until I see how things are going. I think the MPS vs Chlorine is what's confusing me or the Replenish vs Spa 56.

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    Re: Hot tub arrived, water chemistry questions

    Yes, skip the "as needed" shocking if there are not issues. There is no such thing as weekly maintenance. The "as needed" might be weekly, might be every other week, or longer. It's "as needed". The dealer has you all confused. You should add oxidizer/disinfectant after each and every soak. You do NOT just do this for weekly maintenance. Spa water volumes are small so when you soak that is a HUGE demand for oxidizer compared to when you are not in the spa. So you should dose after every soak. Whether you need to dose in between soaks depends on how quickly your oxidizer gets used up between soaks. One advantage with MPS is that it doesn't get used up quickly if there is nothing around to oxidize (i.e. it doesn't outgas) and it also doesn't react with ozone when one has an ozonator.

    So long as you have the silver ions from the cartridge, you don't need to worry about whether you've got MPS vs. chlorine in your spa. That way you don't need to worry about Replenish (mixture of dichlor and MPS) vs. Spa 56 (only Dichlor) vs. regular non-chlorine shock (only MPS). You'd only need to add chlorine "as needed", even if you were to switch to using regular non-chlorine shock instead of Replenish.
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    Re: Hot tub arrived, water chemistry questions

    Ok so for now I won't worry about the as needed part with the Spa56 since the water is crystal clear and doesn't smell weird or anything (just a very very faint chlorine smell when you first open the cover. But it sounds like I could use either the Replenish OR the Spa56 for the post-soak dose? Just in different amounts I would think since one is 15% and one is 99% Dichlor. Since we've been adding the Replenish after each soak (1tbsp / person) it seemed like all was fine but then the test strips were showing 0 FC right before the next soak and then today the test kit was showing 4.6ppm FC. So I think that's what's confusing the heck out of me. I can't tell if we were adding too much because I thought it was low until today and now it's actually borderline too high.

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    Re: Hot tub arrived, water chemistry questions

    Yes you have that right. You use a little less than twice as much Replenish as Spa56. If Replenish were only non-chlorine shock (MPS) then it would take twice as much as Dichlor for the same effect. The amount you need to add depends on how many people are soaking and for how long. It's not the same amount added after each soak unless your bather load is the same from each soak and the time between soaks is the same.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

  17. Back To Top    #17

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    Nov 2014
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    Lake Ariel, PA
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    Re: Hot tub arrived, water chemistry questions

    Ok thanks. Good I know I don't have a bottle of stuff I'll never have to use and can use both in different amounts until they're gone. Bather load generally is the same since it's just me and my husband tho twice he's gone in without me so he's cut down on the Replenish post-soak dose to account for that.

    Any idea why the strips would show nothing on the FC and the Taylor kit shows 4.6? I would think the Taylor kit would be more accurate but it's odd the strip shows not even a slight purple color change.

  18. Back To Top    #18

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    Nov 2014
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    Re: Hot tub arrived, water chemistry questions

    Just to make sure I wasn't nuts, I took a 16oz cup and put a few drops of regular bleach in it and tested with a strip. Off the charts purple so I know the strips are ok.

  19. Back To Top    #19

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    Mar 2007
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    San Rafael, CA USA
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    12,082

    Re: Hot tub arrived, water chemistry questions

    The strips may be showing chlorine and not the MPS level. The Taylor kit, especially adding FC and CC together, will show the sum of both chlorine and MPS. In general, test strips are iffy in their readings.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

  20. Back To Top    #20

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    Nov 2014
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    167

    Re: Hot tub arrived, water chemistry questions

    Ok maybe when we need to add again, I'll use the dichlor (Spa 56) in proper amounts and see if that ends up registering on the strip. Did the weekly maintenance today (skimmer and filter rinsing and water testing). Didn't add the 2 tbsp of Spa 56 as the store recommended.

    pH seems to have crept up from just 2 days ago per the Taylor kit (7.8) but seems to be at 7.6 on the strips so I'm going to keep an eye on that given you comments about CH and TA possibly drifting it up. Alk was 100, CH was 120 and FC was 0.8 and this time I tested further for CC and that was 0.6 so it looks like that really came down from our 4.6 FC reading the other day. We were in it last nite but opted not to dose after we got out. Thinking that I'll dose it tonite with the Spa56 after we get out figuring I want to take it up to 1.5 - 2.0ppm tonite with the dose so that we can read it tomorrow before we get in and know how much it uses in 24 hours.

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