Advice Needed - High CYA, High Nitrates, and Lots of Algae

[PoolDoc]

I was surprised to see the chlorine levels looked pretty good, but there was no noticeable improvement in the algae/green color of the water. I was also surprised to see the phosphate levels were so much higher with the new test (they went from 50ppb to 2500ppb); is this a side-effect of using liquid bleach?

No, it's a side effect of using bogus testing from 2 different companies! I have no idea what your actual PO4 levels are; either number might be right, but it's more likely that they are BOTH wrong!

You can test this for yourself, once you get your pool refilled, by taking a 1 gallon water jug (not milk jug -- it would contaminate the sample) filling it with pool water and then refrigerating it. After 24 hours, take a sample out of the jug "from your pool" to both dealers. Wait 48 hours, and then do it again. All 4 sample results should be identical. If you want to get an idea what the real results are, go ahead and order a K2006 test kit and learn to use it. Then, do a set of K2006 tests on the refrigerated gallon when you take them to the dealers.

By the way, the water in the gallon will NOT test exactly like your pool. Sitting for 24 hours will change it. Refrigerating it should hold any further change to minimum.

Do NOT soak your cartridges in acid, unless you want to have to buy new ones. Acid can 'set' oils, so they can't be removed. It's very, very unlikely you need to clean them in acid. Instead, buy a garbage can that the cartridges will fit inside of, and fill it with enough water to cover the cartridges. Add 1# of trisodium phosphate for every 2 gallons of water. Get PLAIN trisodium phosphate (not: substitute) from Lowes paint department, or this link:

1lb Savogran Trisodium Phosphate (TSP) @ Amazon
5lb Savogran Trisodium Phosphate (TSP) @ Amazon

Add 1 cup of bleach for each # of TSP. Spray off the cartridges, soak for 24 hours, then rinse thoroughly. If any scale is visible after soaking, you can ask about acid cleaning. But it's VERY unlikely you need it.

[PoolDoc]

upgraded membership and moved your post where you can access it. -ben

[capshockeyfan]

Hi Folks,

I just wanted to extend a sincere "thank you" to everyone who posted replies to my previous questions; this Forum is a wonderful resource! I figured the least I could do to show my appreciation was to subscribe and have done so this afternoon.

Since my last post, we did bite the bullet and had our pool drained, cleaned, and refilled; it now looks beautiful. When the water was added, the pool company told me they added 5 lbs. of dichlor as an initial shock. This was not my plan, but was an honest mistake on their part as that is what we had been using the past couple of years when our pool was opened by the same folks. Since the water was added, I have been using Arm and Hammer baking soda for pH adjustments and 6% plain bleach from Walmart as the chlorine source. I have also been using stabilized chlorinating tablets in the skimmer buckets (two tablets in each bucket). I had the water tested this morning and here are the results:

Free chlorine - 1.8 ppm
total chlorine - 1.8 ppm
combined chlorine - 0.0 ppm
ph - 7.7
hardness - 200 ppm
akalinity - 97 ppm
CYA - 10 ppm
nitrates - 0 ppm

I see my chlorine is still a little low and will add some more bleach this evening. My CYA is pretty low and I need to get this level boosted; is it okay to do so via more dichlor shock and or tablets added to the skimmer buckets? If it is best to just add CYA by itself, is there a recommended source? (Our pool is 36,000 gallons.)

I plan to gradually switch to a full BBB pool; and am wondering if it is okay to use up my previously purchased chemicals (tablets and dichlor shock) as long as I am keeping close watch on the pool chemistry? I purchased a 50lb bucket of tablets and a 25lb bucket of dichlor this past spring in preparation of our pool opening and hope to be able to finish them as long as I'm not messing up the pool chemistry.

Sorry if these questions have already been answered; now that I'm a full-member of the Forum I will be able to access previous threads, but I was hoping to get some quick help to these questions. Now that we have basically started from scratch, I'll post new threads when I have additional questions.

[aylad]

Thank you for subscribing to the forum!! The subscriptions go a long way toward helping keep this site up and running.

Keep in mind that baking soda is used to raise alkalinity, rather than to control pH--we recommend Borax to raise the pH and muriatic acid to lower it. HOwever, dichlor and trichlor tabs both are acidic and drive pH down, so if you'll test for it daily, you'll probably find that you don't have to adjust the pH too much. Just don't let it get below 7.0. It is fine to keep using the trichlor tabs and dichlor to keep your chlorine levels up, as long as you stop at the point where you have targeted your CYA. The dichlor will add 9 ppm of CYA for every 10 ppm of chlorine, and the trichlor will add 6 ppm of CYA for every 10 ppm of chlorine--so I would test for CYA every couple of weeks or so, and just switch to bleach when your CYA levels get where you want them to be. Pay attention to the chlorine chart, though--remember that your chlorine levels have to rise when the CYA rises...so once your CYA gets to 20 ppm, your chlorine levels will have to stay between 3-6, no lower!!

Glad your pool is in good shape--now just be diligent about testing, and it should stay that way through the summer! Happy swimming