New User & New Pool Owner - Chemical Issues (Chlorine & Stabilizer Issues)

Hi, I am new to the forum, but have been using it as a resource for a few weeks now. I thought things were going great with our new pool, and I have been maintaining it myself since we commissioned in April.

I had been testing daily with Aqua check strips (FC, PH, ALK, & Stabilizer) but honestly was really just looking at FC & PH. I had been taking a sample of our water to the local Pool Warehouse store about weekly for additional testing.

I have a Trichlor tablet system and would add 1-2 tablets per week to the cartridge and had been adjusting the dial (1-5 range) as needed. All was going well. I was also using a phosphate control and using muratic acid every few days to keep pH in check.

Then I had a few days where I couldn't seem to raise the FC. I accidentally left the tablet dispenser on full (5) and left the pool in service mode running the filter all night. The next day according to the pool store reading my FC was at a 7. Very stupidly and showing my impatience I purchased some "Jack's after shock" to bring the FC levels back down in time for a scheduled pool party the following day. It worked and all seemed okay again.

Another week later I was again having a hard time getting FC to register on my test strips. Got water sample tested again and it showed the following:

FC 0.2ppm
TC 0.2ppm
CC 0.0ppm
pH 7.6
Hardness 155ppm
Alk 100ppm
CA 95ppm

Concerns over lack of Chlorine, low hardness & high CA led us to do the following this past Sunday (7/7/13):

We drained about 4 inches (to lower CA) & refilled (hoping to increase hardness), added 1lb of Zappit to shock & kept our Trichlor tablets full & dial turned up.

I also went and bought a Taylor k-2005 testing kit.

I tested Chlorine levels Monday & Tuesday (today) and they were still zero. I took another water sample back to pool store today and got the following readings:

FC 0.0 ppm
pH 7.6
Hardness 200ppm
CA 80ppm

Hardness has improved, CA is down but not by much at all and still no Chlorine. They now told me I did not drain enough (even though I drained exactly what they previously suggested). They were concerned maybe my tablet dispenser wasn't functioning properly and I should add 2-3 tablets straight to skimmer as well as another 1lb of zappit to shock again (which I have done).

I should also mention that about a week ago yellow algae started to form, we have just been brushing it off. We also cleaned out the 4 cartridge filters.

I just want to know if I am on the right track to prevent the algae from coming back and what to do about the high CA levels. I really don't want to have to waste water and drain again. I had a separate pool maintenance expert tell me there is a product you can use to reduce CA, but when I asked about it at Pool Warehouse they said there wasn't anything.

Thanks in advance for any advice and sorry for the long narrative!

I am assuming by CA you mean CYA (cyanuric acid, also called stabilizer). You are fighting against yourself on your CYA level. You said you drained to try and reduce it but then filled the chlorinator back up with more trichlor tabs. Apparently, you are not aware that trichlor tabs have CYA in them.

You are ok with a CYA reading of 80 but you don't want it any higher, so no more trichlor tabs for your pool. I do not know the ingredients of Zappit but if it has dichlor in it, you also don't want to use that since dichlor also adds CYA.

What kind of pool is this and what is the volume?

Your K-2005 kit is not going to allow you to test the high chlorine levels you are going to have to run as a result of your CYA of 80. (Please read the Best Guess Chlorine Chart in my signature below for more about the connection between CYA and chlorine levels.) But, if you add on the DPD-FAS test (which you can get through the test kit link in my signature) it will basically give you a K-2006 kit which is the one we recommend. The kit you want to pick up is the K-1515.

Go to Walmart and pick up several jugs of their generic unscented bleach. Once you tell us the volume, we can help you figure out how much you need to add.

Repost with the requested info and someone will help you go from there.

By the way, thank you for the subscription. We really appreciate the support!

Thanks Watermom!

Yes I did mean CYA! I know the trichlor tabs have stabilizer, but I was just going by the best advice I was getting at the time (knowing in the back of my head this probably wasn't correct). I have now upon reading your response removed all extra tabs & turned off my tab dispenser.

I just tested the water myself using my K-2005 test kit. My chlorine is now very high, but prob as a result of the shock (Zappit does not have any stabilizer, that much I did confirm). My levels were above what the test would allow, so per the kit's instructions I used the dilution method and used 1.8ml of pool water filling the remainder of the 9ml sample with my house drinking water (we have a filtration system that is supposed to remove most of the contaminants and chlorine). I read the result to be about 1.5ppm which I am supposed to multiply by 5 giving me FC of 7.5.

I also used my test kit to check the CYA levels and I think I read it to be about 100 ppm

I have read the "Best Guess Chlorine Chart" page. I have some concerns about running high levels of chlorine to compensate for the high CYA levels b/c I have three young kids of which one has skin sensitivity issues. We also regularly have friends over who also have little ones and I guess I would feel like I had to issue a disclaimer before we invited anyone to swim. Am I over reacting?

In a best case world, wouldn't it be better to lower the CYA and run Chlorine at 1-3ppm?

Is there any way to lower CYA other than draining the pool? I called my pool company yesterday and they passed me on to a service company. After a brief conversation with this professional, he mentioned that rather than draining the pool I could have used a CYA reducer, but I didn't inquire further b/c I assumed my initial draining of 4 inches would have been enough. When I asked about this product this morning at the pool store, they said there wasn't such a thing.

Our pool is 16,250 gallons, plaster, attached spa, runs 10 hours per day with a variable speed pump at 2500 rpm. We also have an Ozone system attached to the pool (I honestly am not sure what this does for us, all I can remember is that is is supposed to help us use our chlorine more efficiently). I hope this is the type of info you need!

Thanks so much, I am so ready to start enjoying our pool again!

Is it true that the stabilizers in the water rest at the top? I have been draining down to the skimmer, refilling, then rest 6-8 hours and repeat (I was not sure how much time to give the stabilizers to settle at the top after refilling). I have done this three times now. I am not sure I trust my testing abilities, but I think I have dropped the CYA 15ppm to about 80ppm.

I went and bought generic 8.25% liquid bleach and think it is probably time to add as my FC level is now down to 6, I am trying to keep it high while we are in the process of lowering CYA. I was wondering about the procedure of adding bleach. Do I need to dilute before adding, and do I add it straight to the skimmer or poor over the pool surface?

Quote:

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Originally Posted by mrsfish

Is it true that the stabilizers in the water rest at the top?

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Now that is one we haven't heard before! Not true.

As far as adding bleach, you can just pour it slowly into the skimmer while the pump is running.

By the way, you seem to be scared of higher chlorine levels with higher CYA levels. Dont be. It is not a problem and no more dangerous.

Thanks! I have been trying to find a table I saw before which tells how much bleach to add based on its % and how much you want to raise FC... but I can't find it now...

The bleach calculator is in the Forum Q & A section. It is one of the stickied threads at the top.