FIlter pressure high after replacing DE

acamato

0
LifeTime Supporter
May 12, 2008
153
Long Island, NY
Since I opened my pool in mid May my pressure has been at 9 PSI. The past few weeks has slowly raised to 13 psi. Yesterday I returned from vacation and ran my polaris. The pressure climbed from 13 to 20 PSI. I backwashed and replaced the DE, still as 20 PSI. I even replaced the gauge. I do have less flow out of the returns than I have had. I ran the filter in recirc and have improved flow. There has to be someting going on with the filter. What should I do?
 
Denali said:
I would take the filter apart and thoroughly clean the filter grids. Sometimes backwashing doesn't get the job done.

Exactly!!

What most probably happened is the debris from the pool got so embedded that the backwashing can't remove the loaded DE from the grids. Rip it apart and give it a good thorough hosing - watch the bottom of the grids to see if the fabric bows out a lot or if the water stays in the grids for ~30+ seconds -- if so, you'll need to chemically clean the grids.

Welcome to TFP!! -- We'll be here to help with any issues you may encounter with your pool.
 
Update: I took the filter apart yesterday. I found one element with a nickel sized hole. There was not too much buildup on the elements. The new element should be in today and I will put the filter back topgether after work.

Shouldn't the hole make the filter pressure drop? I will post an update when everything is back up and running, hopefully around 10 PSI.
 
As a purely speculative response:

What may have happened is that so much DE vacated the filter through the hole, the other grids were under coated and collected the debris on the grids themselves instead of on the DE coating. This would be a good time to really clean them with a good pressure garden hose, just to liberate as much as you can from the grids.

Before you add new De to the unit, check the pressure gauge to see if the flow is normal - if it's not, you can do the chem cleaning of the grids without wasting any DE :idea:
 
I think it is time to chemically clean the grids. I got everyting back together last night. Backwashed, rinsed, set multi-port to filter, pressure was at 20 without DE.

Do I need to degrease & acidwash or can I just degrease the grids. I have read that you can use dishwashing detergent to clean the grids. Can I clean them in the dishwasher if they fit?
 
acamato
Hello here is a good post written by Waste { he must have forgotten it, he is a busy boy :-D } It's all about de filters .
use-and-care-for-de-filters-t4086.html?hilit=cleaning grids
I wouldn't recommend the dishwasher, but maybe you could try it with the broken one and see what happens. Probally on a low temperature and let us know how it goes, might start a new trend.

Happy Swims
Frank

:lookhere: don't waste on waste!!!
 
Since you had a hole in one of the grids, you might have DE clogging your return lines and that is keeping your pressure high(That's what happened to me!). You can get a little gizmo called a 'drain king' that hooks onto your garden hose and will use pressure to unclog your returns. You can get one at Ace Hardware for about $12. Just do a search on Google for 'Drain King'. Every pool owner should own one! I do my lines a couple of times a year just for preventative maintenance and it only takes a couple of minutes.
 
I have 2 questions. First, when you say the pressure is high, does that mean the suction is low? Our suction is so low, we can't vacuum. And second, how would you use the drain king? I've been trying to get my husband to do something like that, didn't know what to call it, but he's concerned about what will happen. Thanks
 
vykke50
Posted: Wed Jul 16, 2008 6:34 am Reply with quote

I have 2 questions. First, when you say the pressure is high, does that mean the suction is low? Our suction is so low, we can't vacuum. And second, how would you use the drain king? I've been trying to get my husband to do something like that, didn't know what to call it, but he's concerned about what will happen. Thanks
if you want some more answers for this problem you should start a new thread in pool equipment
happy swims
Frank
 

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mtheaded, My return is not clogged because when I have the multi-port valve in recycle, it has a great amount of flow out of the returns.

on another note: I am having trouble locating TSP here on Long Island. Tomorrow after work I will use powdered dishwashing detergent to clean them followed up by an acid wash.

At least my pool is very clear just some debris on the bottom. I will run the polaris tomorrow.
 
Well, I think that narrows it down to your filter itself. If you remove all the DE grids and run the pump, is the pressure still high? My guess s that it will be.
The Recirculate mode bypasses the filter and sends the water through the multiport valve only, and back to the pool. That's why no pressure increase.
The nickle sized hole may have sent enough DE/debris to the botton of the DE manifold and clogged it up.
 
When I uncovered the pool last weekend. I installed new filter grids. I an still running at 22 PSI with new grids and fresh DE. I am going to install a pressure gauge on the discharge/return line after the filter & multiport valve.. This way I can see the differences in pressure in recirc vs. filter. I still don't think I have a return piping leak. If I did I believe that I should be losing water. Plus I have good flow out of the returns.
 
mtheaded said:
Since you had a hole in one of the grids, you might have DE clogging your return lines and that is keeping your pressure high(That's what happened to me!). You can get a little gizmo called a 'drain king' that hooks onto your garden hose and will use pressure to unclog your returns. You can get one at Ace Hardware for about $12. Just do a search on Google for 'Drain King'. Every pool owner should own one! I do my lines a couple of times a year just for preventative maintenance and it only takes a couple of minutes.

The Drain King is useful for clearing clogs. But I don't think it has any useful effect as a preventative. While your hose may have twice (or even three times) the pressure of your filter system, the hose diameter of 3/4" going into 1 1/2" or 2" pool pluming is just not going to provide enough water flow to have any effect UNLESS there is a clog. You won't hurt anything, but IMHO it's a waste of your time.
 
acamato said:
When I uncovered the pool last weekend. I installed new filter grids. I an still running at 22 PSI with new grids and fresh DE. I am going to install a pressure gauge on the discharge/return line after the filter & multiport valve.. This way I can see the differences in pressure in recirc vs. filter. I still don't think I have a return piping leak. If I did I believe that I should be losing water. Plus I have good flow out of the returns.

Sometimes it only takes me the better part of a year to ask the pertinent question :hammer: Is the 22 psi while all the pool returns are running, or just when running the 360? - A pressure jump is to be expected when shutting off the returns to run the 360.
 
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