Considering going bak to tabs..... Am I crazy??

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SupaDave

SupaDave

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Bronze Supporter
Nov 25, 2016
37
Bethlehem, GA
OK
So I've been using the TFP system for some time now. I had originally been using tabs and cal hypo for shock. The TFP system has worked, however I am having to drop test for FC every day and add liquid bleach every day. My pool is in the full So Fl sun all day. Needless to say, lugging around 2 1/2 gal jugs of Cl is a PITA. I understand the relationship between free Cl levels and CYA from all the research I've done on TFP. I understand that tabs continuously raise CYA levels. Luckily, I am on a well here in So. Fl. so replacing large amounts of pool water to lower CYA levels is not an economic issue for me as it is with some. With that thought in mind, I am considering going back to tabs, monitoring my CYA levels, and adjusting same with occasional water replacements. Is this realistic?

Since I am certainly no math whiz, I wonder if some of the smarter folks on TFP could give me some direction on the following......
How do I go about figuring how many, and how often to add tabs to keep a steady FC level that is in line with my CYA level?
My pool size is listed below, and I prefer to run my filter about 8 hours a day.
My current CYA level is approx. 60 so keeping my FC between about 7-9 has worked well for me.
How do I figure out how to keep my FC level at the required 7-9 using tabs?
And is there a way to figure out how fast and how high my CYA levels will rise based on info herein so I will know how often I might have to do water changes?

Again, I must say, I am thoroughly happy with the results I have with the TFP method, I'm just tired of lugging jugs and looking for alternatives. :crazy:

D.
 
Just a couple thoughts before you make the switch.

1. The TFP method keeps me on a schedule for FC testing. Kinda like brushing your teeth...laziness breeds issues.

2. I am no expert, but calculating FC could be hard with pucks. Your CYA will constantly change, and so the amount of FC you need will change daily as well. Too much to juggle for me. The part that makes TFP so successful for me is only having one daily variable to account for among the FC, CYA, PH, and TA. Add another variable and things get complicated regardless of how good our math is. I know they all change a bit, but the FC/CYA is by far the most important factor for me. When they are both moving targerts, it can be tricky.

3. IMHO draining and filling pools is more of a hassle than pouring in bleach. I have to have a couple hours for a drain down that will lower my CYA 10ppm. That's a lot more time needed than dumping a half gallon of 12.5% bleach in a pool. I am on well water too, but I tend to have to adjust ph when I drain down and refill. I usually end up with some cloudy water for a few days as well. You may only need to drain down a couple times a summer, but it just isn't worth the time cost for me to deal with it. My swimming season is most likely much shorter than yours being in MN, so I try to keep it KISS for the 3.5 months of pool season we get.

One option for you could be a LC injector. There are several designs posted on TFP. Once dialed in, it seems like a very good system. Maybe others can chime in on their experiences with a LC injection system.
 
TFP is all about knowing the chem levels and what to add to the water to keep it balanced. If you want to run tabs go for it, you just need to test for CYA more often and then dump the water when you feel the CYA is too high for you to manage the FC/CYA relationship.

If you go to tabs, I would empty about 1/2 the water to reduce the CYA to 30 for a starting point. It will be easier to deal with lower FC levels.

You will need to test often to dial in your pool and see how many tabs it will need.
 
SupaDave,
I am just over the bridge from you. Why not a salt chlorine generator? I did what you're doing, manually adding Pinch-A-Penny liquid chlorine daily for about the first 3 months after my new pool was filled earlier this year. I tell ya, once I turned that SWCG on, I'll never go back to manual. I do spot check my chlorine and pH daily or every other day using my K-1000 drop kit (soon to be replaced by K-2000) but rarely need to add liquid chlorine, I'll bump FC up by 2ppm for a big pool party but that's about it. My pool is about the same size (30K gallons) and I run my SWCG for 9 hrs/day at 100% (my SWCG is undersized) to keep my FC ~6ppm with CYA at 80. I watch my pH and when it gets above 7.8 I add acid to lower it to 7.5-7.6, I may need to add acid a little more often with the SWCG but it's no big deal, if I added Borates I could reduce the frequency even further. At 33K gallons, I'd recommend a SWCG sized for 60K gallons such as the Pentair IntelliChlor IC60. My IC40 installed by builder is adequate for my 30K pool but I need to run it hard, when it dies I'll replace with IC60 or equivalent. We also like the feel of the water with 3600ppm salt required by SWCG. Working great for us! And no more lugging jugs!
 
If you don't want to lug jugs of bleach, I would switch to a SWG. It is much easier to dial in and maintain the proper FC/CYA relationship vs tabs. Tabs will lower PH and TA over time and you will have to be adding borax and baking soda to keep them up. Once you get a SWG dialed in, it is easy peasy with occasional acid to bring PH down.

We recommend SWG be 2 to 3 times the size of your pool.
 
I'll add that you don't need all of the fancy automation to run a SWCG. If you got a SWCG sized for a 60K gallon pool (such as the IC60), you should have no problem generating enough chlorine with it in your current 8 hour pump run time window (assuming you have enough CYA in your water, 70-80ppm recommended), so you shouldn't have to run pump any longer. I have no automation, my pump runs 9am-8pm on its onboard timer, and my SWCG is controlled by an Intermatic mechanical time switch to run 10am-7pm (one hour inside pump start/stop times). But you can run both the pump and SWCG on same timer also. The SWCG does use some power to generate the chlorine, both the IC40 and IC60 draw about 220 Watts according to specs.
 
SupaDave said:
Since I am certainly no math whiz, I wonder if some of the smarter folks on TFP could give me some direction on the following......

1. How do I go about figuring how many (tabs), and
2. how often to add tabs to keep a steady FC level that is in line with my CYA level?

My pool size is listed below, and
3. I prefer to run my filter about 8 hours a day.

My current CYA level is approx. 60 so keeping my FC between about 7-9 has worked well for me.

4. How do I figure out how to keep my FC level at the required 7-9 using tabs?

5. And is there a way to figure out how fast and
6. how high my CYA levels will rise based on info herein so I will know
7. how often I might have to do water changes?

Again, I must say, I am thoroughly happy with the results I have with the TFP method, I'm just tired of lugging jugs and looking for alternatives. :crazy:
Click to expand...

1. How many tabs? one 1lb (16oz) of trichlor tabs will raise FC by 3.3ppm in a 33k gallon pool. How many tabs are in 1lb depends on how big the tabs are.

2. Most pools use 2-4ppm of chlorine per day. Lets use 3.3ppm as it makes the math a bit easier, lol. As your CYA creeps up, the FC sacrificed to the Sun gods will go down.

3. Pump run time to get the FC you need will not be as easy. Probably best to do a trial & error to see how long it takes 1lb to dissolve in your water either though a puck chlorinator, floater or some other system. We don't recommend putting the pucks in the skimmer.

4. see point #1, 2, & 3. Keep in mind the needed FC level will change as your CYA changes. As CYA creeps up, so will your min FC level.

5. How fast will CYA increase? With trichlor, every 10ppm of FC also comes 6ppm of CYA. so with 3.3ppm FC usage, every 3 days you add 10ppm FC and 6ppm CYA. Weekly, 23ppm FC and 14ppm CYA.

6. How high CYA will get will depend on how much trichlor you add and your starting point. See point #5 also.

7. How often to change water will depend on your starting CYA, and then how high do you want CYA to get. If you drain half now to get CYA from 60ppm to 30ppm, then do it again when it gets back to 60, then you have to change water fairly often, dare I say every 2 weeks. That's assuming a FC use of 3.3ppm FC per day. If you let CYA go from 30 to 90, then drain 2/3 water to get back to 30, you are changing every 3 weeks. But remember, as your CYA increases, the amount of FC you actually need to maintain goes up, but your daily usage may remain the same or go down a bit. I've made a big assumption of your daily FC needs.

A better alternative in my opinion is a SWG or chlorine pump system.
 

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Wouldn't using calhypo tablets solve the CYA problem? I understand that calcium hardness will accumulate but CH up to 800 or so is harmless and some of it is naturally diluted by rain.

I'm considering installing a SWG myself. What does the group recommend for a 20k gallong inground vimyl pool? Do you have a favorite brand?

Mike.
 
mikefamig said:
Wouldn't using calhypo tablets solve the CYA problem? I understand that calcium hardness will accumulate but CH up to 800 or so is harmless and some of it is naturally diluted by rain.

I'm considering installing a SWG myself. What does the group recommend for a 20k gallong inground vimyl pool? Do you have a favorite brand?

Mike.
Click to expand...

My vote would be for the Pentair IntelliChlor IC40. This cell is rated for 40,000 gallons (24 hour operation) and would follow the TFP recommendation of at least 2x your pool size. My pool is 30K gallons and I have the IC40 (undersized, thanks PB!) and currently run it at 100% duty cycle for 9 hours/day to keep my FC at ~6ppm with CYA at 80ppm. Since your pool is smaller 20K you should be able to run it at lower duty cycle/for less time, extending the life of the cell. I suppose you could even consider the 60K gallon IC60. The ideal salt level for these cells is 3600ppm in the pool water, I think most pools if they have been chlorinated have salt, I'll leave it to others to comment more on vinyl steel walls and corrosion.....

If you have automation you want to consider that when picking brand of SWCG.
 
mikefamig said:
Wouldn't using calhypo tablets solve the CYA problem?
Click to expand...

There are no cal - hypo tablets for the residential market. They do make them for the commercial market with special feeders. But they dissolve very quickly.

Updated****

I stand corrected. Their are Cal Hypo tablets marketed under NST Chlorine.

Check that out - I am so I can reference it in the future.
 
Teald-
That was EXACTLY the information I was looking for. Unfortunately it looks like I'd be changing water every 3 weeks or so. Since change is a 8-10hr procedure for me, it may not be worth it. When I have my pool dialed in, I am using about 80 oz of Cl liquid per day to cover an approx. 2 - 2 1/2ppm daily loss. Unfortunately, I am having to test FC daily with my K2006 dpd test. Is that a normal testing interval? How often do you test and aren't you going thru a lot of DPD powder?
 
It is recommended that you test FC daily and dose daily when you are manually dosing with liquid chlorine. Officially here are the TFP recommendations: Pool School - Basic Pool Care Schedule

There is also the option of using a liquidator/stenner pump to add chlorine. It is cheaper than a SWG, but you still have to fill the tank up with bleach weekly or bi-weekly.
 
SupaDave said:
When I have my pool dialed in, I am using about 80 oz of Cl liquid per day to cover an approx. 2 - 2 1/2ppm daily loss. Unfortunately, I am having to test FC daily with my K2006 dpd test. Is that a normal testing interval? How often do you test and aren't you going thru a lot of DPD powder?
Click to expand...

Testing every day is the official recommendation. I'm actually going through more R-0871 drops than powder. But I've come to know how much bleach my pool eats every day. at the beginning of this season I tested daily. Then, like you, I found I was adding the same volume of bleach (46oz) every day. I started to go every other day testing, but still dosed the same 46oz every night. I found I could predict where my FC would be before I tested it.
I am currently on my own personal test schedule that I can't divulge because it is a trade secret. ;)

So with 2.5ppm each day instead of 3.3ppm, you could go 18days instead of 14days.
 
Circupool SJ40 and be done :)

I have converted my pool, my hot tub and now up to 2 other pools with the Circupool SJ..

All chlorine ends up costing the same amount in the end, SWG just cost up front.. As far as rusting or parts corroding or anything else, just figure 5%.. If the pump is suppose to last 10 years, it will only last "about" 9 years with SWG, but it may last 11 :)

While it is recommended to test daily, I travel so sometimes I can go a month before testing, the SWG just keeps chugging along
 
SupaDave said:
Unfortunately, I am having to test FC daily with my K2006 dpd test. Is that a normal testing interval? How often do you test and aren't you going thru a lot of DPD powder?
Click to expand...

For daily testing you could get a Taylor K-2000 kit which is DPD drops only (no powder) which will measure free and total chlorine up to 10ppm, also pH. And it has the nice larger #9056 comparator. I ordered one online for $30 and am waiting for it to be delivered. Will be a nice compliment to my TF-100 kit for spot checking of FC and pH. Then use your most accurate chlorine test (with the powder) maybe only once or twice a week.
 

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