DE escaping from the filter into the pool...

[waste]

Wen, welcome to the forum! The hot glue, or whatever it is, sounds like a reasonable way to extend the filter's life for a while (which it sounds like Lee is trying to do). Something to keep in mind though is that you have removed some of the filtration area, for a couple of small patches it shouldn't present any problems, but if the area was substantial, you might regret the quick fix. Also I don't know if the 'glue' would effect the water chemistry.
I'd like to hear from others who have used this method and find out if there are any problems I haven't anticipated. Wen, thank you for a very interesting solution for small tears in filter grids! -Utilize this site to it's fullest and have the easiest and best pool season you've ever dreamed of.

[wen95070]

Waste, Thanks for the warm welcome. I've been monitoring this forum searching for the answer to the problem described in this thread. Up until a year ago, my DE filter has functioned proficiently.

Then, last year I added a phosphate remover which resulted in a 20psi increase in my filter back pressure. At that point I was forced to thoroughly clean the 60sqft of grids. It was then I discovered the hot melt glue along the edges and ribs of the grid fabric (which probably does not reduce the effective filtration area much.) When I recharged the unit, I discovered dune-like slumps of DE forming at the bottom of the pool over the next few days. At the end of a week I drudgingly vacuumed the DE into the skimmer with filter sock. Desperate to break this dreaded cycle, I have inspected the grids thoroughly on several occasions but to no avail.

The pool stays relatively clear until I clean or backflush the filter again. I suspect the leak/tear is eventually blocked by compacted DE that slows or stops additional DE from breaching the grids.

The $1000 question: should I 1) keep looking and vacuuming, 2) replace just the grids, 3) replace the grid and the assembly, 4) replace the entire filter with another DE filter, 5) replace the entire filter with a cartridge or sand filter, or 6) try something else?

Regards,
Wen

[ScottsdaleSwim]

I'm having the same problem with my DE filter.
I have an old Pac Fab Nautilus.
We replaced the grids and still got DE in the pool. I don't know how your filter is built but with ours..a manifold sits on the top of the grids and over a pipe. You can lift the whole unit, grids intact.. out of the filter container. As it lifts off the pipe it has a tendency to bring the rubber O ring with it. When we went to inspect the o rings, that one was gone. AND our strainer for our air relief tube on top of the manifold (inside the filter container) had a tear in it.
We ordered a new one (leslie's replacement had much larger holes) and we're hoping it clears it up completely.
We only get a tiny bit of DE dust on the bottom of the pool now...where before it was a LOT of DE. Each fix has brought us closer to not having any DE in the pool. I'll repost after the new strainer for the air relief tube is installed.
I'm interested to see what your problem is...
Good luck!

[wen95070]

Hi SS, I have an old Pac Fab (PENTAIR) FNS Plus DE Pool Filter. The manifold does sit on top of the array of grids. However, I always remove the manifold and pull the grids out separately to clean. I have inspected the grids, manifold, manifold O-rings, and even the air bleeder (air relief tube?). None seem compromised.

I am, however, headed down your path. As I alluded to earlier, the only question is, will I replace individual field-replaceable units (e.g., grids for ~$200), the whole grid subassembly ~$400, or will I just swap the whole unit for a new DE or cartridge filter for ~$1,000. I am very curious about the new cartridge filters that are supposedly long lived and low maintenance.

Did you replace the grids because you actually found the tear(s)/leak(s), assumed them to be the most likely culprits, or wanted to eliminate them as a possibility?

[waste]

Wen, Scott, (welcome Scott, good choice comming here instead of being 'POOL STORED'), not only is getting the grids to fit in the upper manifold a hastle, if they don't all fit in tightly, de can pass through the gaps, and if that o-ring on the shaft that the manifold sits on is gone or compromised - de will go back into the pool. Another way for the de to enter the pool is by a bad seal in the multiport - in this case it only happens when adding the de, it slips by the gasket and some of it ends up in the pool. Yet another way is to have the pump pushing too much water through the filter for the filter to handle (somethings gotta give ). I'm trying to give the complete scenario. I, personally, prefer sand filters, but they don't clean as well as the others - though they are easiest to maintain. I don't want to tell either of you to replace the whole filter, but if you find you need to, get one with a multiport, you'll thank me. Any questions? - just post and I'll get back to you

[wen95070]

I hypothesized that the DE around a hole in the fabric would show signs of erosion. So, without rinsing off the DE from the grids, I disassembled and examined each panel. As I found these eroded patches, I marked them with a Sharpie.

When I finished searching, I risnsed off the grids, leaving just the demarcations (around holes of varying sizes and shapes.) The air bleeder was in the worst condition, a 1/4" opening at the tip.

I checked and relubricated the O-rings. Then, I sewed up the air bleeder and patched the grids with low-temperature hot melt glue. The MSDS claims that the glue has very low water solubility/ extractives and is stable at pool water temperatures.

When I reassembled the grids, I noticed some of them no longer seated perfectly against the manifold because their frames were cracked. But I figured to get one more season from them before buying a new set.

After vacuuming up the DEbris (sic) at the bottom, I ran the pool pump/filter for several hours with no detectable DE in the pool/spa. I had almost forgotten what "polished" looked like.

Waste, Thanks for your advice and support.

[ScottsdaleSwim]

wen- glad to hear you solved your problem! I received the new air bleed screen and it's just that- screen. The old one was a fabric of some sort. I still haven't installed the new one. I need to drain a little anyway as my cya is off the chart.

Getting those grids into the manifold is tricky and frustrating at times. We replaced the grids because we found a tear in one and a crack in the end that goes right into the manifold. I purchased mine online for 108.00 but I have a 36 sq ft filter area.
Much cheaper than buying them locally.

I'm hoping the new strainer will work and completely clear it. The little bit of DE settles into the liner creases and drives me batty.