Pressure just builds......

[ajwray]

CYA 36
TC 3
FC 3
PH 8.2
TA 109
HARD 140

Realize I have to bring the PH down. I am also going to chemically strip the filter today.

Any other suggestions??

[waste]

Use a detergent or TSP to get the oils off before acid washing the grids.

[ajwray]

Waste...thanks for the advice. It's soaking right now in TSP overnight. In the morning I will rinse well and then do the acid.

[ajwray]

Status Update: The water is almost totally clear but the grids still only go about three hours then I backwash and they need another three hours. Then backwash. I did the TSP soak overnight. Then the acid soak overnight. Vacumed to waste. Current test results:

TC 3
FC 3
PH 7.6
TA 109
CYA 36


20k gallon 16x32


Any other suggestions? Maybe time for new grids (they look fine)? The suction and return lines are fine because the pressue is even when on recirculate.

Help!! I'm selling this house in two weeks and don't want to spend too much more money for a pool I'm not going to enjoy.

[waste]

AJ, what model filter do you have and how much de do you add after backwashing - also what is your backwashing proceedure? (The reason I ask is that there have been a few people recently that have had similar problems due to improper backwashing/ recoating). One last thing, does de come out of the return jets when you recoat the filter?

[ajwray]

Waste, thanks for your continued help...

1. It's a Hayward DE-3600. 36 Square foot grids.

2. I turn off the pump. I hook up the backwash hose. I put the multi-port on backwash for at least 3-4 minutes. Typically, I will wait 1-2 minutes after the little jar on the valve is clear. I turn off the pump. Set the pump to rinse for a minute. Turn off the pump. Set the pump to filter. Add 4.5 lbs of DE through the skimmer.

**I haven't been using the whole 4.5 yet as it was stopping flow. I have been using about half of that does before the pressure builds.

I hope this helps you to help me and hopefully solve the mystery. Right now the pool is clear as anything so something good is happening. There was a lot of dirt (debris) on the bottom not that it was clear and I vacumed that out to waste today which cleared it up even more.

3. No DE is coming back into the pool through the return jets.

[waste]

AJ, here might be the problem, Hayward makes some of the best equiptment out there, unfortunately they don't know how to use it. To backwash your unit correctly:
(Obviously, turn off the pump when changing multiport positions)
Put the multiport on backwash, and watch the sightglass for ~clear.
Rinse the filter till it is ~clear.
Repeat until the 'backwash' cycle is ~clear and rinse again. (~3-5 cycles)
Put it on filter for ~ 1 min. and do another backwash/ rinse cycle.
At this point, you've gotten ~80% of the de out, so only add 80% back in, in your case, it's a little under 4#.
Having way too much, or too little, de in the filter can cause the problem you are experiencing and hurt the unit. Try this a couple of times before you replace the grids.
Good luck in your new home - don't forget to spray-paint 'www.poolsolutions.com' on the livingroom wall, so the new owners know how to take care of the pool -Good luck where you are moving! , if it has a pool stay with this site. Again, Good luck!!

[JohnT]

**I haven't been using the whole 4.5 yet as it was stopping flow. I have been using about half of that does before the pressure builds.

Insufficient DE can cause quick clogging of filters. This is because the grids themselves are doing the filtering because they aren't coated.