High Pressure DE

[indskys]

I have a Hayward 3620 DE filter and i have been having trouble with it running a short time then needing a back wash..the problem is after i backwash and recharge filter i only get about 1 hour before the pressure is 30 psi..it starts at about 15 psi...so i bought new grids and installed them today I got about 4 hours of run time then pressure was back up to 30 psi..now i have the same problem i had before after back wash i get about 1 hour then the pressure is 30 and the flow is very low...i'm stumped..the pool is about 6 years old and the first seasons i only backwashed a couple a times a year...any ideas

[mr_clean]

is this pool filled with algae? if yes, it's worse this year and the filter is just catching all of it doing it's job. Backwash when pressure rises & add DE powder back in & know not as much when starting freshly cleaned or it cloggs up faster.

if no algae, how much DE powder are you adding?
I have seen to many people add way to much.

You say you cleaned/changed the grids etc. the DE was on the outside of the grids correct?

have seen people hook up lines wrong with DE powder being on the inside of the grids causing major problems.

[indskys]

.5 lbs on fresh startup and about 2lbs after backwash...yeah the pool is cloudy but 1 hr to high pressure seems really quick and the grids are in correctly...14 to 30 lbs in 1 hour...i guess i will see better when the pool is clear if ever...

[dj000524]

I am having the same issue. I have a anthony de filter 60sqft. which has center mount verticle grids. Pool is about 12 yrs old and the original owners have changed some things in the filter housing.I bought the house last year and had issues with the filter then. This year I have opened the pool put new grids in. Have backwashed and rinse and added de to the pool. I did have algae at the beginning but all things show that no algae is there but still having high pressure reading after 1hr. I have taken the filter apart and cleaned the new grids along with checking the pipes leading to and from the filter done that today (6/13) and after turning the pump on it started at 18 and w/in 30 minutes was at 30psi. I have even put my multi port valve to recirulcate to make sure there is good pressure to the return jets and there is. Have spoken to several pool people and they are telling me that if a DE filter gets behind it can take several weeks for the pool to clear. At the beginning I was unable to see the second step, but now I can see the third step but thats it. Still cant understand why the pressure builds so fast. I am strongly considering switching to a sand filter.

[McPhee1953]

The Pentair FNS Plus DE filter has been working great till this recent heat wave. I ran the filter for about 6 hours and noticed a "cloudyness" to the water. Then after not doing anything for a few days, algae appeared. For 3 days, I've been back flushing ever hour or so. I've even taken the grid out for cleanings. But the pool is still cloudy.
I inspected the Air Bleed Sock, that sits inside on top of the grid with pressure from a hose ... a hole. This is allowing DE to reenter the pool...thus being picked up by Creepy and building the tank pressure up quickly.

Have you inspected the Air Bleed Sock-Tube?

[waterdog]

Having same problem. First issue was algae, when I made a mistake last month & turned off filter due to traveling for 4 days. Have finally gotten a handle on it (I think) since what was green is now white but water is still cloudy. I have backwashed yet find that pressure is high so water flow slows to a stop in 1 hour. What I end up doing is braking apart DE filter & washing each grid, which lasts for most of the day. What is surprising is when I backwash the outflow water appears clear.Thinking that DE is clogging the strainer on top of manifold - not sure if this is a problem or what else to do.

[dispatch09]

First thing everyone needs to do is take the de filter out and see what the pressure is at when you put the everything back together without the filter in the tank. If the pressure goes down, then you have a problem with your filter. Simplify the process, it is a small trick of the trade.

[elf]

so everyone started having this problem when having a green pool from what it sounds like? When this happens depending on how long the pool has been green can affect a DE filter getting high pressure fast.
You can backwash and clean the filter daily but if you do not have your CYA - conditioner level at 50-60 and your chlorine level at shock level 20ppm until clear with running your pool 24/7 your going to struggle with clearing up your pool.
Filter size will also affect how fast a pool will clearup but having a 60sqft DE filter and the preesure rising fast would seem to me its not at shock level everyday breaking down the algae by killing it with chlorine. Just a 3ppm reading of chlorine will not fix a green pool which can take many days to clearup even at shock level.

[dispatch09]

Does everyone know that you can call the manufacturer of the de filter and they will trouble shoot with you free of charge and they are experts at handling these problems. They handle problems like this all the time. Look on your filter and get the name and model and then look up the name of the filter on the internet unless you already have the number.

[czechmate]

First of all, recommending to someone to raise CYA level 50-60 is a complete BS.
Normal range is 35-50. 35-40 ideal. 50 will require FC of 5.5 ppm which is not the greatest for your skin or the packet book. Further back washing algae clogged up DE elements by pool water is a waist of time and money.
You need to take the cover of your DE filter of and see why. Only force of a jet from water hose will strip the elements clean.
There is no shortcuts, except that it will only take half an hour, instead of half a week of dumping conditioned water to a drain without any results. Sure, it is a little messy but it is the only way.
I only backwash to get rid of organic matter that will accumulate by passing through strainers. Maybe 1 minute twice, usually after extra rain with a water that i need to dump anyway. Than I add maybe 2 coffee cans of DE.
When the pressure is 8 psi over the starting pressure I ALWAYS clean the elements one by one by hose.
Otherwise you never know how much total sq/ft surface is actually working in your filter.

[elf]

starting your pool conditioner level out at 50-60ppm is not BS when a pool is green and full of bacteria and has a conditioner level of 0. High levels of bacteria can lower the CYA level so going on the high side is no big deal. Another reason is alot of people only use unstabalized liquide chlorine and will loose CYA from splash-out/carry-out from pool being used alot. Is 4 ideal? Yes but if the people have kids and the pool is getting pounded on a dailey basis the way I have seen, how long do you think the level of 4 is going to last?

Also if you have just cleaned your filter and the pressure has gone up you can backwash 1-2 times before having to take apart and clean your filter again. I have done this to many pools before when going to a green pool no one wanted to take care of until it was time to swim again.

[czechmate]

I see nowhere statement that CYA was 0. Even at that, CYA of 35 will sustain the shock function of 9 pound of calcium hypo of 65% to do it's job before sun will diminish its potency. Further, if your assumption is wrong and than you need to lower CYA of 60 to acceptable 40 in a 20000 gal average pool, you need to dump 33% of pool water. That is almost 7000 gallon of water, Mr. Elf. BTW, that water may have had Boric acid that cost you pretty penny already.
Forget the splashing, you do not have 3 years and all neighborhood kids to do it, when you need it NOW. Otherwise you would have to maintain FC of close to 7 which is unnecessary, costly and unhealthy to say the least. I am deeply sorry, that I may have insulted your "pool man" ego, Sir, but we should not so easily throw numbers around to a layman pool owners.

[elf]

and how many green pools have you come in contact with in your day that have any CYA in them?
in fact how many pools have you taken care of other than your own pool?

It's great that you watch over your pool and keep it up to snuff good for you.

[czechmate]

Cyanuric acid presence, even at the rate of 60 ppm in the pool, does not prevent pool water from algae formation. That is a fact. If it did, we would not have a need for chlorine. I was under the wrong impression that you know a basic pool chemistry.
To answer your pointed question: Yes I had a CYA 60 prior to my re-plaster and pool was nicely green colored with a happy algae.
This forum is designed to help, not to argue.
I will let Richard explain you this phenomenon if he will feel right to do so.

[elf]

Yes go get chemgeek and have him come explain the secret formula to keeping pools from algae as you are the one getting mad old man. Wow you come in talkin trash because the formula says so but could by chance pools could be algae free with a CYA of 60ppm. the answer is yes!

even if chemgeek does not think so I could careless.

and please do explain how a level of 7ppm of chlorine with CYA of 60ppm is dangerous?
hell I have tested tap water that reads 3ppm.

are we off topic yes but has this been fun yes or should I say yes sir?