I Need Some Help

[leanninms]

I have had a really difficult time getting my pool to clear up. The pool center tells me that everything is balanced. Part of the problem is that when I add shock (calcium-hypo), the water gets really cloudy and stays that way for days. They told me that I could not change to sodium dichlor for shock because it would raise my stabilizer levels over time and my chlorine would not be effective. (I am in the deep south, so algae is a major problem here.) I have already had a mustard algae problem this year that I have treated. Sunday, they basically told me that the water was balanced, there was nothing else that could be done.

Fast forward to today. I took a sample to another pool center that was recommended by friends. Got completely different results. Said the chlorine levels were too high, ph too high, alkalinity was okay but much higher than other pool center's results. Recommended muriatic acid. I came home, backwashed, added the acid, and two hours later, my pool looks 100% better. They said that my shock (calcium-hypo) should not be clouding the water and that I could use the sodium dichlor long term. This pool center uses a computerized testing center. I have no idea if it is accurate or not. I am terrible with reading strips, so it is hard for me to check up on these people.

My question is that with these differing opinions and results, where do I go from here? I have found a calcium-hyo that is 1lb. per 15,000 gallons instead of the 1lb. per 10,000 gallons that I currently use. This would at least keep me from putting too much junk in the pool.

Does anyone have any suggestions or insight? This is our second year in this house with this pool. It has looked terrible both years through 2 different pool centers. I faithfully shock weekly (necessary in this heat), add clarifier and algaecide. I also get weekly testing, but this makes no difference if the testing is not accurate.

Help!

[PaulR]

It is true that dichlor will raise your stabilizer levels, actually quite rapidly; you can think of dichlor as roughly 1/2 chlorine 1/2 stabilizer. Too much stabilizer makes the chlorine much less effective. The chlorine will get used up but the stabilizer sticks around; once you have a reasonable stabilizer level you never need to add it again (except if you replace a lot of water e.g. lots of rain or lots of backwashing).

The calcium-hypo will add calcium to your water, making it progressively harder. Depending on whether your pool is vinyl, fiberglass, plaster, or something else, you do want some calcium in the water; but since the cal-hypo was causing cloudiness, I'm suspicious that the calcium is getting high, especially because you've been using it a lot.

Did you get a written report of the test results from either of these places? If so can you post them? It will help sort out what's going on.

In the long term you are best off using liquid chlorine (sodium hypochlorite) which pool stores and pool departments might carry at 10% or 12.5%; or you can use regular unscented laundry bleach (Clorox etc) which is the same stuff just a lower strength; look for "sodium hypochlorite 6%" on the label.

Some pool stores will think you are crazy for using bleach, but really it works well--it's no more risky than any other kind of chlorine, and also usually the cheapest!

--paulr

[leanninms]

Here is the report from the pool places. The pool is about 30,000 gallons and gunite.

Pool Center #1 (yesterday morning)

ph 7.7

ta 110

cyanuric acid 50

hardness under 250 (can't remember)

free chlorine 3.2

available chlorine 1.0

checked for phosphates and they were not high (not sure about actual levels.)

They recommended adding 1 lb. of granular chlorine (sodium dichlor) to raise available chlorine levels.

Pool Center #2 (today morning)

ph 8.1

ta 160

cyanuric acid 60

hardness 250

total chlorine 8.7

Told me to add 1 1/2 gallons muriatic acid and take some of our chlorine tablets out (other place said to add more tablets to keep levels up because we did not want to use the calcium-hypo shock)

The pool has completely cleared up in 3 hours.

This pool center said that we could use sodium dichlor long term with no problems. Pool center #1 said not long-term.

We did add some water to the pool yesterday, but I don't think that should account for the different readings.

I'm just not sure who to trust at this point. Yes pool center #2 cleared my pool, but do I trust them on the sodium dichlor thing? Pool center #1 said that if we used it long-term we would eventually have to drain our pool because the stabilizer would eventually be too high.

We live in the south. It has not rained in a month. We are adding a lot of tap water due to vacuuming and evaporation (upper 90 degrees every day.) I'm not sure if this makes a difference with the stabilizer situation.

Does this help? Around here, you use sodium dichlor or calcium-hypo. I have never seen anything liquid for shock. No one uses bleach that I am aware of.

Is calcium-hypo known for clouding the water. Both places acted like they had never heard of it. Very curious.

[PaulR]

A combination of high pH, high TA, and calcium hardness can certainly lead to clouding when you add cal-hypo; it creates conditions where the calcium doesn't want to dissolve. Lowering the pH with muriatic cleared it up because then the calcium was willing to dissolve.

The two pool places had consistent CYA numbers, which is encouraging. You really don't want to go much higher on it though, so I suggest you stay away from the dichlor. (Consistent use of dichlor is probably why there is such an algae problem in your area!) If you are going to continue using cal-hypo, then you want to lower your TA and keep the pH down in the 7.2-7.5 range to avoid the clouding problems.

This will be a lot easier if you have your own test kit, instead of relying on the pool stores. They should carry kits that measure pH, chlorine, and TA; if you are doing your own testing you'll be able to manage these parameters much better. Even if you have just a pH/chlorine test kit, that will be helpful.

For lowering TA you should read through Lowering Total Alkalinity. It was written for spas, the process is slower with pools but the basic idea is the same. You don't have jets in a pool, but if your returns have "eyeballs" you can point them upward to get a similar effect. If you don't have any aeration the process will still work it'll just take longer.

--paulr

[leanninms]

A combination of high pH, high TA, and calcium hardness can certainly lead to clouding when you add cal-hypo; it creates conditions where the calcium doesn't want to dissolve. Lowering the pH with muriatic cleared it up because then the calcium was willing to dissolve.

The two pool places had consistent CYA numbers, which is encouraging. You really don't want to go much higher on it though, so I suggest you stay away from the dichlor. (Consistent use of dichlor is probably why there is such an algae problem in your area!) If you are going to continue using cal-hypo, then you want to lower your TA and keep the pH down in the 7.2-7.5 range to avoid the clouding problems.

This will be a lot easier if you have your own test kit, instead of relying on the pool stores. They should carry kits that measure pH, chlorine, and TA; if you are doing your own testing you'll be able to manage these parameters much better. Even if you have just a pH/chlorine test kit, that will be helpful.

For lowering TA you should read through Lowering Total Alkalinity. It was written for spas, the process is slower with pools but the basic idea is the same. You don't have jets in a pool, but if your returns have "eyeballs" you can point them upward to get a similar effect. If you don't have any aeration the process will still work it'll just take longer.

--paulr

Thanks for your help. The funny thing is that up until yesterday, my TA has always stayed at about 80. Pool store #1 had me raise it last week. (10 110) It has always been on the low side with ph on the high side (7.7-7.8). I'm not sure if all the chlorine tabs raised it or not.Can you recommend a reliable test kit for me to use. The strips that I was using are instant read but the color changes as the seconds fly by and I'm never sure when to read it. When I take it out of the pool it is one color; when I walk to the shade or inside to read it, it is totally different.

Thanks again!

[PaulR]

You want the kind of kit where you put water samples in a tube and add drops to it so it turns different colors. For the pH and chlorine tests you compare the color to a set of colored blocks in the kit to figure out your reading; for the TA test you add drops until the color changes, and count how many drops it takes. These tests are more precise than the strips and the color stays steady so you have time to read it.

Walmart carries kits made by HTH and they seem to get reasonable reviews. They even have a "6-way" kit that includes a CYA test; the amount of CYA reagent they provide only gets you 2-3 tests worth, but that's enough for a season in most cases.

Pool stores will also carry kits; the Leslie's chain sells relabeled Taylor kits which are very well regarded. Not sure what other chains sell, but one way to tell is if the store has refills for the kits, see what the refill bottles say; usually they will still have a Taylor or HTH label on them if that's the manufacturer.

--paulr

[leanninms]

Pool store #1 uses kits where you put drops in the tubes. Pool store #2 uses strips and has a digital reader that reads them. I am not sure who is more accurate, but I do know that Pool store #2 cleared up my pool in 1/2 a day. They are a mom and pop store. The owners work there and live practically within walking distance. They have a pool and know what our tap water is like around here, etc. (We add a lot of tap water to our pools around here, so it can impact things quite a bit.) I think I might stick with them from now own.

Our walmart has no testing kits or strips. I was there this morning. Plenty of chemicals, but not one tester of any kind. I bought some strips from the pool store to keep an eye on my chlorine levels more than anything else. They'll do for now. I can't go to the pool store everyday.

I'm still up in the air about what type of shock treatment to use in the future. We are returning the calcium-hypo to pool store #1 this weekend. We are probably going to try a more concentrated calcium-hypo (2 lbs. for 30,000) once and see what happens. If this doesn't work, we will talk to them about liquid shock.

Thanks again.

[PaulR]

Using either dichlor or cal-hypo long term can become a problem that requires draining a chunk of water and refilling. With dichlor you continually add stabilizer, which will never go away and over time make your chlorine less able to keep the pool clean; with cal-hypo you continually add calcium, which can lead to clouding and scale.

Managing an overstabilized pool can work if you supplement the chlorine with an algaecide, polyquat 60 is what I've heard recommended most, I think either weekly or biweekly. Avoid the copper-based algaecides because eventually the copper will start staining the pool.

Managing a high-calcium pool can work if you keep the pH no higher than 7.5 and keep the TA lower than you have been.

Both of these approaches require more fussing than I like, and after a season or two you may well want to replace a lot of water; but that doesn't mean you can't make either approach work for you.

Good luck,

--paulr