New pool owner - first *accurate* test results

[jeffbrig]

Hi everyone!

I'm new to the forums, and to pool maintenance. My wife and I recently purchased a house, and it comes with a lovely in ground pool (info should be in my sig). I grew up with pools (FL resident), but I've never been responsible for maintaining my own. Well, here's a pic I just snapped (I know you guys love pictures)




A little history...after we closed on the house about 2 months ago, the pool was neglected for a couple of weeks while we did some work on the house before we moved in. Sure enough, I noticed the pool turning from blue to greenish - sure sign of algae. I sought immediate help at the nearest pool store (local, not a chain), and they did a fair job getting me the right stuff (liquid chlorine ($2.20/gal), baking soda, CYA, calcium chloride, and acid) to get the pool 'balanced' and back to clear blue. I also bought myself some test strips, then quickly realized just how useless they are. I took a few water samples to the pool store. Each time I went home with more chlorine and other chemicals, and a somewhat lighter wallet. Then I realized their system was a test strip read by a scanner hooked to a PC. Probably better at judging colors than my eye, but still a strip, right? I should probably mention that I have some experience keeping saltwater reef aquariums, so water testing is nothing new to me. In that hobby, we also have the mantra: "Don't add anything you're not testing for."

So, last week I ordered the TF-100, and now I have some data I can actually rely on.

pH: just under 7.8
FC: 10
CC: just over .5
CYA: 90
TA: 90
CH: 475

Now, I'm just slightly frustrated that my CYA is higher than it needs to be - the pool store not once, but twice, told me my CYA was a little low and had me add stabilizer granules. And suggested I throw in some trichlor pucks - I didn't realize how much CYA those could add. My floater is now emptied, and I'll use the remaining pucks if and when I need a little extra stabilizer down the road. Although I recognize CYA is definitely a little high, I'm hoping I can let it deteriorate slowly over the next several months - the combination of high water temps (85-90) and bright sunlight should help that along, right?

For chlorine, the pool store had suggested I add about 2 gallons of 10.5% liquid chlorine per week. I've been doing 1 gallon a week (and all at once, should probably split that up). My last addition was Monday, and I'm at 10 today. Seems ok for my current CYA level. It looks like my pool's chlorine appetite either isn't as high as they estimated, or the chlorine was REALLY high a while back. I'll have to do more measurements over time to get a handle on that. The pool store was also pushing "shock" on me every other week or so - I believe it was Shocktrine - potassium monopursulfate 45%. After reading here that you only really need to shock when you have a problem, I'm going to hold off on that for now. Last addition of Shocktrine was probably a month ago. Since then nothing but a bottle of liquid chlorine per week.

CC went almost completely clear on the first drop, just a slight pinkish tinge remained. That's why I'm calling it a little over .5 rather than 1. Is that a fair way to judge the test, or should I consider it .1? It's been cloudy (and rainy) here the last few days, so not much sunlight to help break down CC.

Calcium is higher than what I see recommended, but is it an issue? The pool is plaster - diamond brite, I believe. Previous owners had the pool resurfaced about 2 years ago. Is 475 ok?

pH is towards the high end of ok, right? The previous owner told me the pool tends to have pH rise over time, so he dosed a little muriatic acid periodically to keep it in check.

Any general thoughts of suggestions? How am I doing?

 

[jblizzle]

Welcome to TFP!!!

Well you are off to a fairly good start

Unfortunately, the "high water temp and sun light" will not lower the CYA. The CYA is only lowered through physically removing water (backwash, splashout, draining, etc). Although it does slowly break down like around ~3ppm per month or so.

You should really be testing and adding chlorine every day (maybe every 2 days). You will actually lose less chlorine to the sun by not raising the FC level so high. Use the FC/CYA Chart and just keep it above the minimum.

If it took 2 drops for the CC test, we would call that 1.0ppm which is higher than you would like and could point to a need to SLAM the pool. You had algae, you think the water is clear after your pool store experience. But, we recommend the ShockLevelAndMAINTAIN Process to ensure it is all gone. You could elevate the FC level up some and Perform the Overnight Chlorine Loss Test to see if there is still anything living in the pool. You are right though that the slightly elevated CC may just be a lack of sun.

The higher CH just means that you will want to keep an extra close eye on the pH and never let it get above 7.8 to avoid potential calcium scaling.

Have you started using PoolMath to calculate dosages? The CSI (kind of an advanced topic) at the bottom shows how balanced the pool is with regards to impact on the pool surface.

 

[tim5055]

So, last week I ordered the TF-100, and now I have some data I can actually rely on.

pH: just under 7.8
FC: 10
CC: just over .5
CYA: 90
TA: 90
CH: 475

Now, I'm just slightly frustrated that my CYA is higher than it needs to be - the pool store not once, but twice, told me my CYA was a little low and had me add stabilizer granules. And suggested I throw in some trichlor pucks - I didn't realize how much CYA those could add. My floater is now emptied, and I'll use the remaining pucks if and when I need a little extra stabilizer down the road. Although I recognize CYA is definitely a little high, I'm hoping I can let it deteriorate slowly over the next several months - the combination of high water temps (85-90) and bright sunlight should help that along, right?
y clear on the first drop, just a slight pinkish tinge remained. That's why I'm calling it a little over .5 rather than 1. Is that a fair way to judge the test, or should I consider it .1? It's been cloudy (and rainy) here the last few days, so not much sunlight to help break down CC.

pH is towards the high end of ok, right? The previous owner told me the pool tends to have pH rise over time, so he dosed a little muriatic acid periodically to keep it in check.

Any general thoughts of suggestions? How am I doing?

First, welcome to TFP Beautiful pool - deep water - ocean access with no fixed bridges I will assume.... But I digress

CYA only degrades a couple of ppm per month. Not enough to count on to get your numbers in line. Temperature/evaporation doesn't help. When water evaporates from the pool, the CYA stays behind. So, sorry to give you teh bad news but unless you have a gaggle of kids with lots of splash out water that you replace the only way to fix this area is to drain water and replace it.

pH is at the upper end of recommended. If you have any water features or again the kids splashing around expect it to rise. Aeration (ie water movement) makes pH go up. Stop by Lowes and pick up a gallon of muratic acid from the paint department. Blue label is the strong stuff you want. But, South Florida seems to have fair pricing on acid and chlorine at the pool stores.

The CH will coe down with the CYA when/if you drain. The water there is not that hard, so fill water shouldn't drive that much higher.

You are doing great!!

Test & adjust FC & pH daily. Check that plus TA & CH on the weekends and CYA only if you change out a bunch of water.

Go swimming!!

 

[timerguy]

Nope only replacing water will lower cya. I've seen that folks say it will lower 3ppm/ month all on its own, but that hasn't been my experience. You should be using that test kit you bought daily for FC/CC and pH and adjusting as necessary. 2.20/gal is a fantastic price for liquid chlorine. Use pool math to help you with Chem recommendations and dosing amts.
Sure is a pretty pool!

 

[jeffbrig]

jblizzle, Yes I have pool math calculator open right now. The CSI with the current chemistry is -0.03, which looks to be very good. The pool is finally getting some sun today, so I'll retest FC/CC this evening and see if that gives me a better CC number.

Tim, haha, I wish I had deep water access - but I'm close to 7 miles inland. If I had deep water access, I can assure you there would be a dock and a boat out there.

timerguy, that 3ppm/month loss is exactly what I was thinking. I did read a post on here recently that someone else in S Florida was seeing more like a 3-5ppm monthly drop, and chalked that up to the combo of high water temps and sun.

The way I see it, I have two options. Wait and see what happens, and hope I don't develop any serious issues while CYA is high. If I'm lucky, it may come down a few ppm/month. Or it might not. Option two is to go ahead and drain ~25% (3500g), which should get me to CYA 70 and CH 350. Pool level is actually really high right now due to rain this week, so I need to dump some water no matter what, otherwise levels will rise as it evaporates back down. I don't necessarily mind keeping my CYA a little towards the high end, as the pool receives NO shade, and I'm contemplating a SWG after we settle in to the house.

My other PITA is a somewhat balky pump (also needs to be resolved before considering a SWG). It cuts out some during the heat of the day - full afternoon sun doesn't help. No weird bearing noises or anything though. I know this is generally a really bad sign for the pump, so I already picked up a spare motor, just haven't switched it out yet. Electrically, it checks out fine on my multimeter - proper 230v, etc, so I suspect the pump may have a sensitive temperature sensor. With the cover off the back of the pump, it doesn't shut off at all. Of course, I can't leave it open. If I could find my air compressor spray nozzle, I'd blow out the cooling ports - but it's hiding in a box somewhere in the garage, lol...

 

[jblizzle]

Is the motor sitting in the sun as well? Might try to give it some shade and see if that helps some.

Any chance you thought ahead enough to upgrade to a 2-speed motor as it would save you a good bit on electricity costs?

 

[jeffbrig]

Yes, it's on the west side of the house, so it gets plenty of afternoon sun. It has a motor cover, but I don't know how effective those are.

No, I didn't have the foresight to go for a 2-speed. With all the stuff going on trying to get into the new house, I just pulled the numbers off the old motor and ordered a direct replacement.

 

[timerguy]

Cya of 70 will require a higher FC level than it would @50. I'd suggest you get it down to 50 since you don't have a swg. That will save you some $$$$ in the long run. On the other hand, if you're serious about getting a swg in the very near future, then you'd probably be OK taking it down to 80 instead of 70. I'm talking about a month as very near future, not next year. You'll love the convenience of a swg!!!

 

[jblizzle]

Cya of 70 will require a higher FC level than it would @50. I'd suggest you get it down to 50 since you don't have a swg. That will save you some $$$$ in the long run.

Assuming the pool was clean and clear (no algae), then the higher CYA would not cost more money to maintain, in fact it should be less as less FC would be lost to the sun. BUT, if algae appears and a SLAM was required, then the chlorine cost would be higher than they would be at a lower CYA level. AND if the required FC level is about 10ppm, then there are the issues with the pH test not working.

IMO, I see no urgency to lower the CYA from 90 as long as adequate FC is maintained and no algae appears. IF you have to SLAM though, then I would dump half the water first.

 

[tim5055]

IMO, I see no urgency to lower the CYA from 90 as long as adequate FC is maintained and no algae appears. IF you have to SLAM though, then I would dump half the water first.

I can agree with this, and it was exactly what I did. I started 200+ and dumped lots of water to get it below 100. Once I was below 100 I have been getting it down with rainwater additions and probably back-washing/vacuum to waste a little more than I might need. 70 today.

Jeff,, if you are 7 miles in, looking at the canal I'm guessing Plantation. I was in Davie/Cooper City for a long time.

 

[jeffbrig]

Tim - amazing guess. You are right on the money.

 

[tim5055]

Tim - amazing guess. You are right on the money.

Too much time on my hands driving around Broward in the past......

 

[jeffbrig]

Just a quick update. I re-tested FC/CC today

FC: 9.5
CC: <0.5

On the CC test, adding the reagent barely put any color into the water. Adding 1 drop of R-0871 cleared it on the first movement, no swirling needed. So it looks like the sunlight yesterday broke down whatever CC I registered yesterday morning. Looks like I'm in pretty good shape as far as any organics in the water.

I took a look at the bottle of acid I have from the pool store, and was surprised to find it's sulfuric, not muriatic. Digging around on Google, it seems that's somewhat common in S. Florida, although I see some people mentioning concern of sulfate accumulation. I plan to look for muriatic acid the next time I'm grabbing chemicals though.

 

[pwrstrk]

Going forward I would target FC at 11 and never below 7 for a CYA of 90. That'll give you some wiggle room so you don't fall below your FC min. ?

 

[jeffbrig]

Still trying to get a handle on my pool's chlorine needs. A couple of weeks ago, I thought about a gallon 10.5% bleach per week was keeping me where I needed to be. Although it's possible that was cemented in my mind mind while I still had a trichlor puck in the floater.

On Monday I tested and found FC was 4.5, when I expected it to still be around 7. I added full gallon, which should have taken me back to 12, but did not re-test. I just checked this morning, 4 days later, and FC was just 2.5! Ran to the pool store, got more liquid chlorinator, and added a full gallon. According to pool math, this should have taken me to an FC of 10. Re-tested a few minutes ago, and it's actually just 8.5. So either my pool is quite a bit larger than I estimated....or the liquid chlorine isn't as quite strong as indicated on the bottle. Now, the old bottles I finished this week were about a month old (stored on my patio - shaded but warm during the day) and could have deteriorated, but the stuff from the pool store I would have expected to be pretty close to full strength. Guess this just confirms the need to test regularly, and not just rely on the calculator and expectations.

Of course, I also pressure cleaned around the pool deck one evening this week, so I'm sure I got a little nasty runoff from that into the pool (no chemicals, just water and whatever mildewy stuff came off the pavers). And the lawn was mowed Wednesday, which always results in some extra dirt and grass clippings blowing into the pool. Both of these would probably increase chlorine consumption.

On the CYA front, I've been taking advantage of rain to dump water whenever I can, and I'm headed the right direction - currently I'm measuring a CYA of 80.

I'll keep an eye on chlorine consumption through the weekend, and decide if we need to SLAM or not. CC was just .5 (1 drop) when I tested this morning. Water is still blue and clear.

 

[jblizzle]

You should be testing and adding chlorine every day. Chlorine is a consumable and lost to 2 things: organics in the water and the sun.

It is normal to lose 2-4ppm of FC every day. In your pool that would be 37-75 oz of 10% everyday ... so about 1/2 gallon every day.

 

[jeffbrig]

Wow, 4ppm seems like it would be a ton. If my consumption is anywhere near that, it'll be an easy decision to go for a SWG, just to avoid lugging the bottles around....

 

[timerguy]

You might consider doing the fc/cc test every evening at the same time and dose your fc back up to the recommended level. That way, you should be able to better establish your approximate daily fc loss. I'd bet your water temp stays higher for longer than mine up here in SC. Currently, my water temp is around 70 and my fc loss is a little less than 3/ day.

 

[tim5055]

Jeff,

It's a pain, but daily testing for a few weeks at least it needed. You need to get a feeling for your pools chlorine consumption.

Install a Stenner pump and just fill the tank every two to three weeks.......

 

[jeffbrig]

I'm posting this for any other new member that may be reading. It seems my 8.5 FC reading was suspect on Friday. I don't think I gave it enough time to mix completely. Saturday with the pump running, I measured again and got 9.5. The only possible explanation is that I read it wrong on Friday (pretty hard when just counting drops), or my pump hadn't run enough to fully mix the new Chlorine I had added. So - give your pump plenty of time to mix before taking new readings.

So this morning, with the pump running and after skimming, I read 7.5 FC. Which seems like my "normal" rate of consumption (no rain, no swimmers) is closer to 1ppm/day. I added a half gallon, which should put me back at 11. I'll keep measuring every day or two this week and dose as needed.