P-R:

I really appreciate that sometimes you make a business decision for its long-term impact. A family-owned pool store working SO hard for you is one you want to give business to. I'd do the same--in fact, I do give biz to one store that has higher prices because they EARN it with the help they've given me over the years.


The pool chem company's chemist is going to recommend company-sanctioned options--like buying cal-hypo.

You CAN use it--I'm sorry if I was unclear--but I'm not a fan of it. Water can be cloudy until it dissolves, and, if hardness goes too high can also make it cloudy. Cal-Hypo can also drive up pH.

If you now have your test kit, test your Calcium Hardness (or just Hardness) and your total Alk. (I think your T/A is 100--"99" is a meaningless #) If your hardness stays under 500ppm and your T/A is 100 your water should stay clear once it dissolves in.

I'm trying to figure out why they prefer it--and all I can think of is that since it takes time to dissolve they are thinking you'll have a residual chlorine level in your water longer.

But I still would go with LC--the amount you figure to add is:
1 gallon of LC (12.5%) will add 12.ppm of FC to 10,000 gallons of water. So it takes 3 1/3 gallons to get that in your pool...Ballpark is that 4 1/3 gallons gets you to about 15ppm--so might as well make it 5 gallons.

You are DEFINITELY fighting something but now your FC is 1 and your CC is 1 so it's getting there.

I don't know of a better way. The ONLY thing I can think to do is a newer, more intense version of our method, which is do-able on a weekend. But you MUST have the FAS-DPD test to do it. That's to have many, many carboys of LC--like 5 or 6. Add one in the morning and test the water 1/2 later. If the FC isn't at shock
level, add more LC. Do this every half hour until FC reads at shock level and continue measuring it and adding LC whenever it drops off. The idea is to NEVER let the FC drop below the killing level to absorb what ever is in your pool.

There MUST be some contaminant--either that or you've got some really nasty and resistant to chlorine bacteria growing in there. Something's there that ordinary tests don't show--and I don't think it's phosphates either--and we know it's not ammonia, but must be something similar that's not "living"--like bromine.

You may want to consider a full water replacement--Poconos has a method that doesn't risk damaging your liner--involving a huge sheet of plastic--you add new water on top and drain the old from below and there's always pressure on the liner.

Unless you are willing to keep up the LC regimen, I must admit I'm coming to the end of my ideas.

Chem_Geek, Waterbear, Mods, Marie? have you got any other ideas?