NEED HELP with an Apollo VA-38 DE Filter

[Ecrivan]

Hello,

Love this forum so far and the invaluable information it has provided, as well as the unending help from other pool owners/users.

I have an old Apollo VA-38 DE filter with brand new grids (38 sq. ft.), a new o-ring, and a new pressure gauge. When there is no DE on the grids, the operating PSI appears to be 12-15.

If I add the recommended amount of DE to my grids (1 to 1.5 lbs per 10 sq. ft.), this amounts to 4-6 lbs, so I usually put in 5. No sooner do I do this when my PSI slowly rises to around 30-35, effectively doubling the PSI when there's no DE on the grids. The other result is very little water moves in my pool. The returns jets barely push out anything and the skimmer barely takes in anything.

However, when I put less than 5 lbs on the fresh grids, I find that they barely get covered, which defeats the purpose of having a DE filter.

I feel like I'm trapped. Please help!

 

[Bama Rambler]

What does the water look like?

It sounds like the filter is doing its job.

You're using pool filter DE aren't you?

 

[Ecrivan]

Right now, the water is blue but cloudy/milky. I just finished the steps outlined on this forum for turning my green swamp back into a sparkling oasis. The water has remained at shock level (using bleach) for a few days, and an OCLT has confirmed that there is no more algae present. And yes, I am using DE filter media specifically designed for pools.

I am concerned because 1) the pressure seems to be too far above the normal operating pressure for my filter (or any DE filter)--hardly any water is moving, and 2) there is not enough flow to move my pool cleaner (which is suction-based).

Logic tells me that if the PSI is 12-15 without DE on the grids and climbs to around 30 when I add just 2 lbs (of weighed) DE media to the grids, then if I add the recommended 4-6 lbs, the PSI will shoot to over 50, which is the MAX operating pressure of my unit.

I have no idea what to do or what's wrong. Should I remove one of the grids?

 

[Bama Rambler]

I believe it's just catching the dead algae that's left in the water as soon as you add the DE. DE filters are great unless you're clearing an algae outbreak. It's not uncommon to have to clean it more than once an hour.

 

[Ecrivan]

If that's the case, then it does so in a hurry because it climbs from 15 to 30 in about an hour. Should I let it run overnight? According to the instructions for clearing algae, I need to run it 24/7 until the water is no longer milky/cloudy. But I'm scared of the pressure building too high.

 

[Bama Rambler]

Your pump will only produce about 40 psi top end so you won't damage anything by letting it run. It won't clog enough to completely stop the flow through the filter so you can leave it running. However if you are worried about it, you can shut it off overnight and run it during the day when someone can watch it more closely. We don't normally recommend that, but you have to live within your comfort zone.

 

[Ecrivan]

I read elsewhere that either there could be DE inside the grids, clogging them up (though I don't know how it would get in there), or that the skeleton inside the grids could be broken, causing them to squeeze together (preventing water flow) when the DE is heavy on the outside and the pump sucks water through. I am going to disassemble the grid unit today to check for both.

But my biggest concern is still being able to put the required amount of DE on the grids. I can't get more than 3 lbs on there before the pressure is pushing 35 PSI.

 

[techguy]

My DE filter will have the pressures rise from clean to max pressure is in less than 15 minutes if I am using my vacuum and the pool is dirty. This weekend, I could not run my filter for more than 2 hours without bumping it.

Last year, when I had a big bloom, it would plug the filter and have the pressures rise in less than 3 hours. When it was getting close to requiring new DE, less than 30 minutes with just the return via the skimmer.

If your DE is plugging up quickly, it means you are getting a ton of junk out of the water in quick time. This is the advantage and disadvantage to a DE filter. It filters reallly well and your water gets crystal clear, quickly. The drawback to the ability to rapidly remove the junk in the water means you need to attend to the filter more often. What takes a sand filter to clear in a week of near 24/7 pumping (low work demand/long filter time) can be accomplished in a weekend with proper "baby-sitting" (high labor requirements/short run time).

 

[Ecrivan]

Techguy and Bama Rambler, you were both right. Basically, my DE filter was just doing it's job. In about 3 days of babysitting it and backwashing it daily, it cleared the pool. And I still am at a decent pressure. I'm going to clean it one more time, then start the Borax process. I can finally start using my pool this weekend.

 

[techguy]

OK... well I had to clean my DE today. It was the worst I have ever seen... in 7 years. I could only run the skimmer about an hour before needing to bump.