Hayward Sand Filter - Need Advice

[Chevydude057]

I'm experiencing a weird phenomenon with my 150# sand filter. I'm just opening the pool for the season and my water is a touch cloudy, as to be expected. Slam and run the filter, right!?

Well every couple of hours (somewhere between 60 and 90 minutes) my pressure increases and the water pressure out of the outlet becomes weak. I did a deep clean when I opened the pool, there wasn't really a lot of junk in the filter. Some sure, but nothing egregious.

Normally I wouldn't think much of it, but I've back washed 8 times now in 3 days and the water out of the backwash isn't even dirty.

So I grabbed my SlimeBag and put it on the pool, and set the multiport to recirculate. My thought is it bypasses the filter, if the bag "clogs" and pressure rises in an hour or 2, then it's really just capturing a lot of junk that I can't see. Well, I've now let the pump run for 12 hours and the pressure has only gone up 1.5psi with the slime bag. I shut it off and cleaned out the bag, and quite a bit of debris came out. Way more than the 150# sand filter each time.

The weird part, if I shut the pump off for an hour and turn it back on, the pressure is right at 15(baseline) so the same amount of time and then it acts like it's getting clogged through the sand filter. If I turn it off for a minute and start it back up, it looses pressure again in a couple of minutes, which seems normal for a sand filter getting clogged.

I've had trouble with my sand filter before letting dirt and debris by the filter and not capturing it. The only thing that seemed to work was a new diffuser basket. That being said, I don't know what to open and or check inside the filter. Anyone ever experience someone similar? I'm wondering if during operation something is changing inside the filter.

 

[borjis]

Can you post a set of water test results?
I'd also do an overnight chlorine loss test.
This sure does sound like algae. Beginning phase you don't really see it but it will clog a filter. A possibility.

 

[Chevydude057]

Can you post a set of water test results?
I'd also do an overnight chlorine loss test.
This sure does sound like algae. Beginning phase you don't really see it but it will clog a filter. A possibility.

Sure.

FC: 5 maybe 5.5
CC: .5 maybe .25. Think the second drop might have made a small difference?
CYA : Just below 30.
Calcium : 110
Alkalinity : 40

I do agree it sounds like Algea. I've just never had a filter clog this quickly and with the filter problems I had two years ago I'm worried something is wrong with the equipment.

 

[borjis]

Try the overnight chlorine test. If there's a loss it's probably time for a slam.

 

[Chevydude057]

Try the overnight chlorine test. If there's a loss it's probably time for a slam.

I checked the FC last night at 21:00, it was at 10.0 or 10.5.
This morning at 06:00 it was the same, 10 or 10.5.

I'm never sure if that extra drop makes a difference.

The pool is a touch cloudy, but it doesn't seem to change unless I let the filter run up to 20psi, but the problem is the water doesn't circulate as well because the outlet pressure from the return jet slows.

I decided to try something, I took a small submersible pump, and the ladder mat and put them in the center of the pool. I left the pool filter running this morning at 21psi and the submersible pump is on a timer. There's no hose connected, so it's just going to "waterfall" the water inside the pool and keep things moving. Hopefully it'll create some movement and extra circulation in the water and I can get the Crud out.

I am just trying to determine why my filter seems to struggle and collecting anything smaller than a dang golf ball. I exaggerate, I know but it seems worthless.

I have absolutely no problem slamming if I need to, worst case I'm losing .5 FC overnight. But the filter doesn't seem to be catching much. Yesterday I back washed into a 55 gallon barrel, and the backwash was clear. A tiny bit of gunk at the bottom, like a shot glass full. That seems crazy to that that's enough to clog a 150# filter. Everything has been replaced, the gaskets, I've tried a new multiport valve, the fingers have been inspected, the diffuser basket, etc. I really don't want to replace the filter if I can't determine what's actually wrong with it.

 

[Chevydude057]

Hey Everyone, I definitely need some help here. Just for sanity, I have done an OCLT three days in a row.

My CC is .5 and the OCLT my max loss was .5 FC the first day. Every other day it was 0.

But it seems like I have Algae in the pool. But, it only happens when I run the filter. If it sits for a day without the filter running there is nothing. The filter runs for an hour I get something in the bottom of the pool. I have used skimmer bags and they don't seem to help. They collect a bunch of junk but a ton still settles at the bottom of the pool.

Is dead algae going to be dark?

It seems to me (and I'm a beginner here) that my filter and circulation is not great. The skimmer doesn't seem to collect much, and the Sand filter seems to catch even less. Like the pool water doesn't actually get mixed up and circulate.

Just for a test, I collect a bunch of the dirt/algea, I slowly poured it into the skimmer and I could literally see it coming out of the return jet.

But I did inspect the fingers, the sand is only 2 years old, it's been deep cleaned and backflushed, the level is correct. I even checked the multiport valve to make sure it wasn't put together wrong, and it's correct. (Like the filter setting is actually sending water through the filter).

There's a lot of information here, but I guess my biggest question is why does Algea only settle on the bottom of the pool when the filter is running? Shouldn't it grow/multiple regardless?

 

[Chevydude057]

There's a lot of information here, but I guess my biggest question is why does Algea only settle on the bottom of the pool when the filter is running? Shouldn't it grow/multiple regardless?

Anyone have any suggestions for this? The more I run the filter the more Crud I get at the bottom of the pool. The water is clear otherwise and brushing doesn't seem to get it into the skimmer.

I used a submersible pump to try and collect it and put it directly into the skimmer basket to try and collect it and that keeps it from being on the floor.