Trying to wrap up my SLAM....i added DE to sand filter...is this supposed to happen?

Jump to latest Follow Reply
C

crocop

0
May 5, 2016
161
Toronto
So I have been slamming for 6 days now, and although all the aalgea is gone, and I can see the bottom of my liner in shallow end, the pool is still cloudy.

My current numbers.

FC 14
CYA 30
CC 0

I added 3 cups of DE to my sand filter last night and watched it closely. 3 cups was enough to raise the PSI by 1. After added, it raised my PSI like 10-15 points every 1 to 1.5 hours.

is this normal? I just backwashed and added 3 cups of DE again. Once again, had to backwash agfter 1 to 1.5 hours. I did this about 3 times.

Should I leave the DE in there longer?

This morning the water did look a bit clearer, but I did not want to leave the DE in overnight because I guess someone bad can happen if I let the PSI keep rising right?

Am I doing this DE thing right is my question?

Should I just add 2 cups and let the PSI rise at a lower rate? Or will it not work then?
 
What you're describing is normal.

You were right to not put in the DE when you couldn't check pressure. You're doing everything right.

Try the 2 cups. It may take longer to load up, but it may also filter less efficiently. Or it could be that 3 cups was overloading it. You'll know by how long it takes to load up. My guess is not a whole lot longer than it takes with 3 cups.
 
This is exactly what happens when adding DE. It works very well, but requires constant attention for me. You can try to add a little less DE, but at the end of the day it is capturing the junk which then requires frequent backwashing.

You should try to maintain the same backwashing frequency, i.e. 25% rise over clean pressure even with DE. This can be very labor intensive, but its good to know just how much junk you are removing. One option to wait on DE for a few more days and just "polish" the water near the very end when your pool is mostly clear. Either way you'll get there it is just a balance of time vs. effort.

As for the increased pressure, I don't know that it will damage anything but I would not recommend it either. IMO it is just that the pump can not overcome the resistance of the filter so it just wastes the power spinning but doing nothing.

Update - common practice for me to get sidetracked responding. As always, I defer to Richard if anything we post contradicts ;) You are good hands with his advice.
 
Pool Tool said:
This is exactly what happens when adding DE. It works very well, but requires constant attention for me. You can try to add a little less DE, but at the end of the day it is capturing the junk which then requires frequent backwashing.

You should try to maintain the same backwashing frequency, i.e. 25% rise over clean pressure even with DE. This can be very labor intensive, but its good to know just how much junk you are removing. One option to wait on DE for a few more days and just "polish" the water near the very end when your pool is mostly clear. Either way you'll get there it is just a balance of time vs. effort.

As for the increased pressure, I don't know that it will damage anything but I would not recommend it either. IMO it is just that the pump can not overcome the resistance of the filter so it just wastes the power spinning but doing nothing.

Update - common practice for me to get sidetracked responding. As always, I defer to Richard if anything we post contradicts ;) You are good hands with his advice.
Click to expand...
We didn't say anything contradictory to each other.
 
I did this last weekend. I back-washed multiple times a day for the first few days and like you I didn't leave it in overnight. I was was trying to backwash at a 30% raise but it hit 50% a couple times. After the first few days I haven't noticed anything unusual, I haven't back washed since Monday and PSI is stable with 3 cups. It worked great, my water looks awesome.
 
Richard320 said:
What you're describing is normal.

You were right to not put in the DE when you couldn't check pressure. You're doing everything right.

Try the 2 cups. It may take longer to load up, but it may also filter less efficiently. Or it could be that 3 cups was overloading it. You'll know by how long it takes to load up. My guess is not a whole lot longer than it takes with 3 cups.
Click to expand...

Thanks. 3 cups brought the PSI up 1....and then took about 1.5 hours to get an increase of 15...
will try 2 cups today to see the outcome.

Its nice seeing the light though!

I know the DE should and could be used more to "polish" the water, but I'm a little eager :)
 
crocop said:
Thanks. 3 cups brought the PSI up 1....and then took about 1.5 hours to get an increase of 15...
will try 2 cups today to see the outcome.

Its nice seeing the light though!

I know the DE should and could be used more to "polish" the water, but I'm a little eager :)
Click to expand...
Those of us with DE filters use DE all the time. It's not just a final polish. The reason we tell sand filter people to wait until things are cleared up some is because of the huge amount of backwashing needed. If you're good with the backwashing, you can use DE from the getgo and all season long, too.
 
Richard320 said:
Those of us with DE filters use DE all the time. It's not just a final polish. The reason we tell sand filter people to wait until things are cleared up some is because of the huge amount of backwashing needed. If you're good with the backwashing, you can use DE from the getgo and all season long, too.
Click to expand...

ah ok got it.

I guess the constant backwashing is also lowering my CYA, so I should watch out for that.
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply