sand filter vs cartridge

[jkane2007]

I checked a couple of things last night and here is what I got
PH 7.2
FC 12
CYA 50
We have two three inch pucks in the skimmer, and I added a couple of pounds of PH+ (not sure of exact brand, will repost) and 2 gallons of Namco liquid shock. I will check levels again tonight. I had to brush the sides again to keep the green (algae?) from accumilating. filter is running 24 x 7 right now.

[CarlD]

OK. Take the pucks out. They are making the pH go down and the CYA go up. Unless you have a good reason to raise CYA over 50 its a good place to stop.

PH+ is overpriced, seriously overpriced Arm&Hammer Washing Soda (not baking soda), that sells here in NJ for .80/lb It's soda ash, aka, Sodium Carbonate. So is Washing Soda.

Namco Liquid Shock is merely 12.5% Liquid Chlorine...double strength bleach. I buy the stuff when it's on sale because it gives me 1 gallon jugs that I KNOW are safe for 12.5% I then refill them from 5 gallon carboys of 12.5% which is far cheaper. Two gallons should raise your FC level by 10ppm, which may bleach your liner a little, as 22ppm is higher than the 15ppm we recommend, but probably not, is my guess.

Carl

[jkane2007]

should I continue to keep the FC high for a couple of days?

[aylad]

Yes, when fighting an algae bloom, you need to keep your chlorine at shock level for your CYA until the pool clears, the algae is gone, and you are not losing more than 1 ppm of chlorine when testing at night after the sun is off the pool and again in the morning before the sun is on the pool. After you've met all three of those conditions, then you can let your chlorine drift back down into normal ranges for your CYA.

Janet

[Poconos]

There is a trick of adding a little DE to a sand filter to get better filtration if you're looking to trap really small stuff.
Check this thread:
http://www.poolforum.com/pf2/showthr...to-sand-filter
The first post tells you the process. If you do this just keep a close eye on the pressure as it will rise quickly if you're catching stuff.
You then backwash and start again. If you really have a mess, like I have at times, I just do a quick backwash to dump most of the crud. I don't try to get the BW water totally clear until I've eliminated most of the crud. Saves water.
Al

[Watermom]

Also note that when you add the DE, the pressure may not rise instantly. Mine takes about 20-30 minutes. So don't add more if you don't see the rise immediately. If after a half hour or so you don't see a 1 psi rise, then add a little more.

[jkane2007]

Thanks I will give the DE trick a try this weekend.