Hi all, we have a Hayward DE 3620 filter that is roughly 2 yrs old. Pool was installed in late 2022. Each year it was closed and opened by the company that installed our pool. We have consistently had DE coming back into the pool and being picked up by the robot vacuum. I was told by the install company that it’s either a crack in the filter which is unlikely since it is new, or I am adding too much DE but have confirmed that I am not by multiple sources. I even had a 2nd opinion maintenance company come to diagnose the issue. They pulled apart the filter and inspected the fins and couldn’t find any cracks, added more DE after rinsing it all off and the problem stjll persists. Any other suggestions of what the issue may be?
DE in pool
- Thread starter Gproulx731
- Start date
There is most likely a small hole in the filter grids or the top collector manifold and can be hard to find.
Adding too much DE just clogs the filter and will raise the pressure.
Adding too much DE just clogs the filter and will raise the pressure.
- Apr 10, 2018
- 6,452
- Pool Size
- 18375
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Are you sure that's what you are seeing is DE? Is your robot able to collect a sample?
The pressure doesn’t really ever get too high. I’m not sure how often one is supposed to backwash but i may only need to do it once a week based on the gauge. Could this also be a symptom of a problem?
I’m not certain however when I clean it out of the robot it leaves behind the white film for a few days on the ground as I believe DE does
- Apr 10, 2018
- 6,452
- Pool Size
- 18375
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Ok. There've been a couple recent threads where DE was confused for calcium precipitate. If you have any doubts, drop some muriatic acid on the white stuff. If it fizzes, it's calcium based.
Does the DE enter the pool the entire time the pump is running? Or only at start up? Is it possible the plumbing is draining out when the pump is off? Are you sure the filter is assembled correctly? I had an issue with DE returning pool and traced it to an improperly air relief screen. Kinda reaching here, but looking for alternatives to a torn grid.
Does the DE enter the pool the entire time the pump is running? Or only at start up? Is it possible the plumbing is draining out when the pump is off? Are you sure the filter is assembled correctly? I had an issue with DE returning pool and traced it to an improperly air relief screen. Kinda reaching here, but looking for alternatives to a torn grid.
I will try this, thanks. But I feel like that would be quite a bit of calcium. Would it be calcium if the plaster is still curing? It is a newer plaster pool and I am still fighting to keep pH down too, however after 2 years I figured it would be fully cured by now. I don’t know anything about filter assembly but with 2 different experts looking at it I would assume if anything was awry it would have came up by now
- Apr 10, 2018
- 6,452
- Pool Size
- 18375
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Let's deal with those questions if you confirm calcium. Calcium will have more of a crystalline appearance than DE. DE will tend to puff and become suspended in the water when disturbed.
It could be dirt or sediment from the environment or even dead algae.
Can you post a full set of test results from your K-2006 test kit.
Once you clean your filter (remove the grids, etc) and put it back in service with the proper amount of DE - that pressure after the pump finishes priming is your BASELINE pressure. Take note of it.
When your pressure rises 25% above that number then it is time to backwash.
For example, if you are at 16psi (baseline) and it rises by 4psi (25%) to 20psi then that is time to backwash.
Also, if you have a variable speed pump, always check the filter pressure at the same speed. A higher speed will increase pressure so always check pressure at the same speed.
You should only backwash monthly at most. Some people monitor the 25% increase and others may just backwash monthly whether it has reached 25% higher or not. Obviously, the latter could use more DE over time.
Another idea if you wish to test it - backwash your filter, add DE (80% of the normal addition) and turn on pump. Watch the return. If you have a hole in the grid or in the manifold or air screen - DE will shoot out of the return fairly quickly. You would see it as a cloud coming out of the return. If not, then it may be some other issue.
