Confessions from an unrepentant do-it-yourselfer

[BeerHat]

Hi all, thanks for all the support you've given to pool owners. I'm amazed by the quality and amount of information here.

I had a small 8000 gal vinyl liner pool at my last home and have just purchased a home with a considerably larger pool. It's been about a month and now that the weather is warming here in Northern California, the water temperature has risen to 80 degrees, which seems to be enough to make a good environment for the algae bloom that started on my walls about a week ago. I had the levels balanced out (PH 7.4) but probably did let the chlorine get a little low (busy with moving :) ). I know by the best practices chart I can shock at 25ppm+ to clear the algae, but another problem I have is the CYA level reads about 200 (off the chart of my Taylor k-2006 test kit, I'm extrapolating).

My FC is about 20.5 (CC .5) and I'm afraid at my CYA level, I haven't shocked it to a high enough level. Problem is, I have so much stabilizer that

1) Not much chlorine is available to fight algae
2) It will take forever for levels to come down, during which time I can't gauge PH (test doesn't work with high chlorine levels, right?)

I guess my only option at this point is to partially drain the pool to lower stabilizer levels. I was hoping to fully drain the pool in a couple months after checking the function of the anti-static valve (if I even have one).

Am I on the right track? Is there anything I can do without draining to help? I should mention that the water is clear and at current chlorine levels seem to have stopped algae growth from progressing, but there's noticeable algae covering about 30% of the pool walls.


Phil

[BigDave]

You can operate a pool at high CYA levels but you'll need to know how high.

Dilute the pool water with an equal measure of tap water and test the mix - if it's 100 or less, multiply by 2 for your CYA. If it's still over 100, Mix one part pool water with two parts tap water and measure the mix and multiply by 3.

pH readings may be a problem, I've read somewhere that if you let the phenol red test sit for a while it gets closer to the correct color. Theres also the option of electronic pH tester but if you go that route, you'll need to handle it gently and calibrate it regularly with a standard solution.

[kelemvor]

Is there anything I can do without draining to help? I should mention that the water is clear and at current chlorine levels seem to have stopped algae growth from progressing, but there's noticeable algae covering about 30% of the pool walls.

If you are sure that your CYA is 200 and not higher (via dilution testing) then as you are already doing you can operate with high cl as you already are. You seem to have already consulted the chart, and know where your numbers need to be.

If it were me, I'd do a partial drain to replace some of the water and reduce the CYA level.

It seems I'm just confirming what you already know; you either have to shock to a high enough level based on your CYA or reduce your CYA by replacing (some or all) of the water. Pick one, and do it - or do both?

Don't forget to brush the walls and run the pump 24x7 while cleaning things up.

[BeerHat]

Thanks BigDave, I thought the dilution trick would work and that it should work for chlorine levels off the chart too... I was surprised the gentleman at Leslies didn't do that for me, but I'm beginning to understand those guys aren't necessarily rocket surgeons.

Kelemvor, yes, you are confirming what I *think* I know, but needed confirmation from someone with experience. Thanks. I didn't know brushing and running pump continuously would help... will do.


Phil

[BigDave]

rocket surgeon - I'm laughing out loud. I'm going to repeat that.

As Kelemvor said Brushing will be necessary to keep the slimy off the walls. Brush Brush Brush is part of BBB.