Pool pressure is good but System loses flow

[edub30]

Need the teams help. I have 35,000 gallon inground pool with a hayward DE6020 grid filter and whisperflow pump. When system is good the water flows output flows water from the jacuzzi to rhe main pool. The issue is that I cant keep the water flowing. I felt that ive tried everything. Everything works well when i backwash,clean the filter and grids and adding new DE but the water will only flow well for about 4 hours and then both the vacuum and output pressure is weak. The pressure gauge after I clean the filter stays consistent at 30psi and is around 35psi when it loses flow a few hours later. I’ve cleaned the filter out multiple times during a week and still the same issue and not able to effectively circulate the water in my pool. The skimmer basket, pump basket are all clear of debri. Not sire what else to check. Please help.

 

[mknauss]

Welcome to the forum!
The picture you show appears to be very clear water. However, the action you describe is 99% of the time algae clogging the filter.
Can you post a full set of pool water chemistry test results from your own kit? Have you used any pool store potions in the past? Your initial filter pressure seems quite high. Has the filter been run without DE in it?
I suggest you read through Pool Care Basics - Trouble Free Pool and even look at a few of our videos TFP-TV - Trouble Free Pool

 

[Rancho Cost-a-Lotta]

Welcome to TFP!

 

[edub30]

Thanks for the warm welcome. So I did have algae and I was shocking the heck out of it and the algae would come back the very next day. I had the water tested and turns out that my phosphates was through the roof. I put some no phos to get it down and is in nominal range. I did backwash and didn’t recharge the DE and ran for like 4 days. But since then I did clean out the filter grids with fresh DE like 3 times in a week and still get the same result of low flow. I do recall the Leslie’s sales rep say that Inwould have to run clean the filter after adding the phos remover which I did multiple times. Do you think it’s because I have a lot of dead algae residue in the pool and it’s clogging up the grids and just have to keep cleaning the grids until it resolves itself? Any other recommendations? My system also isn’t setup to drain to waste.

 

[wireform]

I think your not getting out of your troubles because you have one big decision to make first. Is it the TFP way or Leslie's but it cannot be both. We don't give advice on pool store testing as they carry very little true value. You need to buy one of
Test Kits Compared these kits and read the links below.
Pool Care Basics
FC/CYA Levels
PoolMath
SLAM Process
Overnight Chlorine Loss Test

 

[Rancho Cost-a-Lotta]

1. Stay out of pool stores
2. Get one of the recommended test kits. The kits from Tftestkits.net provide the best value
3. Add 5 ppm of liquid chlorine per day until your test kit arrives. PoolMath will help with the calculations
4. Post results when your kit arrives
5. Read and prepare for the SLAM Process

 

[mknauss]

I did backwash and didn’t recharge the DE and ran for like 4 days.

That is not good. DE Filter Use and Care - Further Reading

I suspect you should follow the SLAM Process. You will need a proper test kit as described above.

Next time you wish to address phosphates, use a quality remover. Orenda is one. We rarely believe you need to do anything with phosphates.

 

[edub30]

Test kit ordered. I’m a first time pool owner and just found this site while trying to troubleshoot. Since then I’ve been educating myself and prefer to learn since I’m an engineer by trade and rather diy. Every time I go to Leslie’s to test water I feel like they are wanting to rape me with no Vaseline. Thanks for all the advice and quick responses. I’ll continue reading the link provided and see how it goes. Thanks