Very high pressure with my DE filter

InMaine

Active member
Jun 12, 2024
39
Maine
So I have read every thread here about high pressure even after repeated backwashing but I still have questions. I didn' get my pool open until mid-June. I had my water clear after about 4 days of constant vacuuming, brushing and backwashing. But I didn't have a test kit (the TFPro is ordered, due to arrive any day) so I had to rely on the pool company's water tests for chemical needs. 15# of calcium chloride was added over the course of about 4 days, a small amount of soda ash (Arm & Hammer) and 6 gallons of liquid chlorine overnight and 3/4 gal muriactic acid. The green went away, the pool cleared. I was then adding 3/4 to 1 gal of liquid chlorine 3 times a week. My filter was humming along and the water was sparkling blue and clear. But then a faint green tint started appearing here and there at the top third of the walls so I shocked with 5 1/2 gallons of 6.5% liquid chlorine which turned the clear blue pool to murky green pretty quickly but after running the filter overnight, the water was clear and sparkling again. I filled the chlorinator up with Tri-chlor tabs since it was really sunny and hot and I didn't want to slide backwards with liquid chlorine burning off fast in bright sunny days and my CYA is under 50. But black spots on the floor were appearing and seemed to be multiplying every time I looked. Not solid black spots, blotchy black spots. I'm not 100% sure when they started but they weren't there while doing the constant vacuuming/ backwashing opening procedure. But that's another issue, first I need the filter to run. I can't run my fliter for more than 1 or 2 minutes. When this first happened about 3 days ago, the filter had been running fine, pressure under 20, then later the afternoon this started, it hit 28, so I backwashed. It started up like usual, the water and some air coming out the jets strong for a few seconds, then settling into a nice flow with a ripple across the top of my water. But within seconds it went to 20, then a few more seconds 22, then to 28 within about a minute. So I backwashed again. Same thing. I backwashed again and put the hose in the pool so the level stayed up. I went and put 1 pound of powder in the skimmer but stopped because I could see the flow getting less out of the jets. The pressure was high again. I let the water level come up withy the filter off and came back an hour later and did a longer backwash. The backwashed water is running out clear. But on filtering-start up, the same pattern with all over again, normal pressure around 12-15 then shooting up to 30 near instantly. I shut it down, left it alone starting around 5 pm yesterday. But this morning, it's the same, strong start with the pressure at 12-15 but then shoots to 20-ish and then 25, 28, 30 within a minute. My plan is to take the filter apart and see what's going on inside. Is that my next step? I will hose off, scrub a little and soak the grids to make sure they are clean. (Oh, I have no leaks.) But of course, the algae is having a party now in my pool. It is very hot and sunny.
 
Algae are overwhelming your filter. You will need to baby sit it.

Add 5ppm of liquid chlorine a day until your kit arrives, then SLAM. Link-->SLAM Process
Add chlorine without filter running? I can only run filter for a minute or two. Then the jets show no return and the system sounds like it is really hurting and going to explode with like small ticking sounds.
How much chlorine is in gallons with no idea what there is now?
 
And why is the water running out clear friom the start of backwashing?
Also, do I not need to break the filter down tio clean the grids? If I don't, I don't want to d it for nothing because it is always hard for me to get that belly strap on well. (not to be a sexist, but I am a 67 year old woman)
 
Use PoolMath and your pool volume to determine how much liquid chlorine to put in to add 5 ppm of FC to your pool daily until your test kit arrives and you can test.

It may be beneficial to open your filter up and completely clean the grids and filter housing.
While you have the grids removed - and after cleaning out the filter housing - close the filter up (without grids) and see if the flow issue is still present. This will let you know if you have a blockage or if the grids are filling up with algae.
If there is a blockage - not grid related - you will need to find and fix the blockage. If there is no blockage (grids removed) you have a chemistry issue (lack of sufficient chlorine and algae). Then put the grids back in the filter, reassemble and add the required amount of DE (a full charge, not the ~80% used after a backwash).

Let us know the outcome and let us know when your test kit arrives (what does tracking indicate?).
 
If I don't, I don't want to d it for nothing because it is always hard for me to get that belly strap on well. (not to be a sexist, but I am a 67 year old woman)
It doesn't matter your age or gender - those band clamps are a pain in the butt to install by yourself.
Someone on here made a "U" shaped hook out of some heavy wire to put in the two holes near the nut. The "U" would need to be big enough to fit easily when reinstalling the band - it holds the band together while you install the washers, spring and nut. You remove the "U" after you tighten the nut a bit.

Hopefully someone can provide a link to that post as I can't find it.
 
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It doesn't matter your age or gender - those band clamps are a pain in the butt to install by yourself.
Someone on here made a "U" shaped hook out of some heavy wire to put in the two holes near the nut. The "U" would need to be big enough to fit easily when reinstalling the band - it holds the band together while you install the washers, spring and nut. You remove the "U" after you tighten the nut a bit.

Hopefully someone can provide a link to that post as I can't find it.
Oh, that made me feel so much better than it isn't just my ineptness, thank you! Ya, I'd love to see what you're talking about to make it easier.
 
While you have the grids removed - and after cleaning out the filter housing - close the filter up (without grids) and see if the flow issue is still present. This will let you know if you have a blockage or if the grids are filling up with algae.
If there is a blockage - not grid related - you will need to find and fix the blockage. If there is no blockage (grids removed) you have a chemistry issue (lack of sufficient chlorine and algae). Then put the grids back in the filter, reassemble and add the required amount of DE (a full charge, not the ~80% used after a backwash).

Let us know the outcome and let us know when your test kit arrives (what does tracking indicate?).
Great idea to test it witout grid. But you do know that means I have to do that clamp thing twice arrgh!!
I took the grids out, hosed them down and now soaking in a light acid/ water solution in a trash can. How long do I have to soak them?
 
Ok, it actually went very well. I tested the system without the grids while they were soaking and the perssure stayed low around 15 so that gave me peace of mind that there was no other issue. When I replaced the extremely clean grids back into the filter and added powder the filter ran smooth and low like it should. I kept it going all night.

I have a new issue now, not sure but I think I'll start a new thread on it.
 

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I didn't start a new thread. My TFPro kit arrived right after I wrote that and I got into it immediately. What is the STIR BAR? The white cross shaped plastic thing?
Great - update your signature to delete "(hasn't arrived yet)".

Also, in PoolMath, turn on log sharing. PoolMath should use the same email and password as your forum account. This will let us view your logged/saved test results.
 
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It seems hard to me to know exactly what my pH is with using that color match thing. $150 and that's how I determine the all important pH number?
Also, When doing the TA test, I am to add R-009 until the green solution turns red. So does that mean when it changes from green to pink or do I continue adding drops of R-009 until it turns to a true red? I got to 13 drops and it was getting darker pink, like reddish-fuschia but not really red. Does it go to a real red if you keep adding R-009 or is the first "version" of red, meaning the instant it turns pink as opposed to green is when you stop the test?
 
Post a picture of your PH block with water and reagent added we'll help.

Pink is fine. Add drops until the color no longer changes, and subtract that last drop.
 
Post a picture of your PH block with water and reagent added we'll help.

Pink is fine. Add drops until the color no longer changes, and subtract that last drop.
Ok, so if I stop adding and counting drops as soon as it goes from green to pink that will change today's TA result. I kept adding until it got to dark pink because I wasn't sure what red meant. So can I edit today's log?
 
For both the TA and CH tests - continue adding drops until the last drop doesn't chamge the color. Then subtract that last drop from the total.
So if drop 14 changes the color and drop 15 doesn't change the color, your drop count is 14.
 

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