High pressure after adding DE to sand

[mjob1999]

Had a pretty bad algae problem when I opened up this year and have been in SLAM for a while and can pass an OCLT. I’m pretty sure algae is gone. I have never added DE before but was hoping it would speed up the water clarity issue.

I added DE according to instructions (diluted 1/4 cup in a bucked, poured into skimmer, repeated until pressure went up 1 psi.) I knew that the pressure would probably go up pretty quick. So I checked after 3 hours. Baseline is 11 spa, with the DE it was at 12. When I checked it read 20 psi. I quickly backwashed and repeated the DE additive procedure. 3 hours later, it was at 20 again. Same thing happened a third time.

My question is this: is it normal for this to happen multiple times? I backwashed it this time and didn’t put DE in it since I can’t check it overnight. Should I keep doing it until the water clears? As long as I can watch it that is?

Thanks in advance for any help!!

 

[Bperry]

Had a pretty bad algae problem when I opened up this year and have been in SLAM for a while and can pass an OCLT. I’m pretty sure algae is gone. I have never added DE before but was hoping it would speed up the water clarity issue.

I added DE according to instructions (diluted 1/4 cup in a bucked, poured into skimmer, repeated until pressure went up 1 psi.) I knew that the pressure would probably go up pretty quick. So I checked after 3 hours. Baseline is 11 spa, with the DE it was at 12. When I checked it read 20 psi. I quickly backwashed and repeated the DE additive procedure. 3 hours later, it was at 20 again. Same thing happened a third time.

My question is this: is it normal for this to happen multiple times? I backwashed it this time and didn’t put DE in it since I can’t check it overnight. Should I keep doing it until the water clears? As long as I can watch it that is?

Thanks in advance for any help!!

I’m not a fan of the DE thing but some people around say it works to speed up the process. Is the pool water getting any clearer faster?

The SLAM has two other criteria to know of alage is gone. You lose 1ppm or less FC overnight and have 0.5ppm CC. You generally do those tests AFTER the water is clear of algae. What are your latest test results?

 

[mjob1999]

CYA is low, since I haven’t put any in to start the season (20) so my SLAM level is 10. Have been holding it there. The sun is eating it up during the day but my OCLT revealed a loss of only .5. The cc cleared up with one drop.

The water does seem to be clearing better. But that’s kind of subjective. Might just be me hoping the DE will help. I’ll be able to watch it this afternoon so I am going to restart the DE process and see what it does. I know a sand filter does take a while to clear the water especially if it is backwashed. I know it catches more fine matter before it is backwashed than after.

I’ll keep holding the line. I’ll post how the afternoon goes with the added DE. It may very well be that it is really catching that much fine matter.

Thanks

 

[Bperry]

CYA is low, since I haven’t put any in to start the season (20) so my SLAM level is 10. Have been holding it there. The sun is eating it up during the day but my OCLT revealed a loss of only .5. The cc cleared up with one drop.

The water does seem to be clearing better. But that’s kind of subjective. Might just be me hoping the DE will help. I’ll be able to watch it this afternoon so I am going to restart the DE process and see what it does. I know a sand filter does take a while to clear the water especially if it is backwashed. I know it catches more fine matter before it is backwashed than after.

I’ll keep holding the line. I’ll post how the afternoon goes with the added DE. It may very well be that it is really catching that much fine matter.

Thanks

SLAM is supposed to be done with CYA of 30 mininum. Your FC burns off faster if its lower thsn that.