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

[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