DE returns to pool, Pool guy says new filter time?

[mobilenemo]

Hi All,

Pool rookie here. Purchased the house with pool about 2 years ago. Last week I noticed the pool had DE all over the surface. My pool guy says the DE is returning to the pool because the filter (pentair FNS plus 48) is old and needs to be replaced. The filter was last cleaned by the pool guy in April and I didn't noticed any issues then. I searched the forum and found that torn and/or cracked grids or cracked manifold is typically the reason why DE returns to the pool.

So I took apart the filter (first time) and found no tears on any grids but the small grid is cracked and floppy. The 7 large grids have minor crushed ribs. Should all these grids be replaced anyway? The manifold has a crack that is not deep but can still be felt by dragging a fingernail over it. Should the manifold be replaced as well?
The retaining rod nuts were a bit rusty but turned ok. The bottom spider looked ok as well.

Based on online research, I'm guessing the filter was manufactured back in 2005. I spoke to leslie's pool supply and they said the entire filter should be replaced. I'd rather just replace the internal parts unless the filter is indeed on it's way out.

I've attached upclose pics of the manifold and small grid.
Another question, the DE powder on the filter was a light brown green color, with some layers being white grey. Is this normal for a filter that was cleaned back in April? Or is it just time for a cleaning? Pool load has been minimal since april.

any help is appreciated Thanks!

 

[jblizzle]

You can get a full set of grids for under $150. If the manifold is cracked I would replace it as well. Still cheaper than a new filter. Another thing to check is the seals on your backwash valve.

You should backwash when the pressure rises 20-25% over the clean pressure. And a good idea to break it down once a year for a thorough cleaning.

 

[mobilenemo]

Updated the OP with photos...

Thanks for the suggestion jbizzle. I was leaning towards replacing the grids and manifold, just wanted confirmation.

 

[jblizzle]

As long as the shell is in good shape, it should last awhile ... there is really not much that can go wrong with these filters.

The grids in current house were much worse than those we I got it and was still functioning. All were crushed some and finally just got too hard to put back together ... got a new set and life is great

 

[Bama Rambler]

I agree with JB, just get a grid set and a manifold and you should be good.

Spend some time here learning about how to take care of your pool and equipment and you won't be at the mercy of the pool guy.

If the light brown/green color on the grids is algae you should also start learning how to properly manage your pool water.

 

[mobilenemo]

I replaced all the grids and manifold. i think DE is still returning to the pool. These two pictures were taken 10 days apart. the first photo is after the pool was vacuumed. What should I check next?

 

[brian10]

check the gasket in the multiport valve.

 

[JamesW]

Add one pound of DE to the skimmer while the system is running and watch the returns for one minute. If DE is getting through, you will see it.

Is the pool painted? It looks like the surface is deteriorating and that might be part of what you are seeing.

 

[techguy]

i can't tell of sure but it looks like you have a low level algae bloom going on.

Do see DE in the chipped paint or is it algae?

 

[Bama Rambler]

Tie a thick sock over a return and then add the DE. If it's returning to the pool the sock will catch it.

 

[mobilenemo]

Pool was painted by previous home owner. Currently saving for a replaster job.

I'm not sure if it's DE or algae in the chipped paint. But I'm leaning towards it being algae since new DE is normally grey/white in color...

I'll try the sock over the return. Are athletic socks (white, crew, etc..) ok? Do I need to open the filter and clean off the existing DE before adding DE into the skimmer? The filter does not have a multiport or push/pull backwash valve.

 

[techguy]

I don't have the same filter but I do have a DE without any valve or backwash setup. I isolate the pump/filter from the pool and then I let the DE settle to bottom of the filter body (about 30 minutes is normally enough for me). I then remove the belly band and take the head (and the DE filter tubes) off and wash them using a garden hose. I am lucky for the waste DE. I can drain some of the water and then dump the dirty DE slurry into my green-waste recycle can.

I think with most grids, you can drain them into a backwash hose. I have heard of some people using pillow cases to trap the dirty DE if they do not have a separator or backwash line. When the head is off the filter, you can then wash them with a hose.

 

[vinper]

when you shut pump off does the strainer basket water drain back to pool ?

 

[techguy]

No. Once the pump basket is clear of bubbles, it starts full. Is so not have any back flow. IIRC the filter has a check valve in it to prevent back flow.

Sent from my SCH-I535 using Tapatalk 2

 

[techguy]

I was looking at my answer and I have a different setup as I have an above ground pool. This means my skimmer is always above my pump. If I need to fill my pump strainer, all I need to do it open the lid a tiny bit and it fills very quickly all over the ground. AG pumps are not self priming and canno pump air. If I get a large bubble in my pump strainer body, I cannot pump water and the pump sits empty.

An IG pool pump is "self priming" and will pump air to create a vacuum to draw water to the pump. BUT, that being said, once it fills the pump strainer and pipe from the skimmer to the pump, it should stay full. If it leaves your pump strainer, I would start with the strainer lid at the pump. First check and lubricate the o-ring, then determine if the pump lids is warped/cracked or otherwise damaged. If it's sun faded and crazed, it may be worth replacing on principle.

 

[mobilenemo]

Ok so I tied a white crew sock over one of the returns and left it there for 4 days. I didn't see any DE or brown stuff in the sock.

i do see some bubbles in the pump baskets. The water doesn't drain out of it when shutting off the pump. I ordered a new filter tank o-ring and relief valve since the orings had some tears in them. Will replace on the weekend.

Water test from today:
FC 2
CC 1.5
TA 130
CH 350
CYA 80
PH 7.8

 

[techguy]

Time to SLAM the pool. Your CC indicates you have stuff you need chlorine to finish removing.

 

[techguy]

Also, your FC is too low for a CYa of 80. You may have a full bloom on your hands real soon.

 

[mobilenemo]

Ok so on 7/23/13 I added a Gallon of 12% liquid chlorine.

On 7/25/13, I started the SLAM
reading's prior to beginning SLAM
FC 7.5
CC 0.5
TA 130
CH 400
CYA 100
PH 8.2

I used the pool calculator and:
added 1/2 gallons of 14.5% acid to bring the PH back down to 7.5
added 6 gallons of 10% liquid chlorine to bring the FC to 39
ran pump for 24 hours


Today, 7/26/13 I get these readings:
FC 26.5
CC 0
TA 260
CH 370
CYA 90
PH 7.8

Since the CC=0, do I need to keep SLAMing?

 

[Soupy]

You stop SLAMming when you meet three criteria: the pool is clear, CC is <= .5, and you pass the overnight chlorine loss test.