Coating the grids of a DE filter with a variable speed pump

Jump to latest Follow Reply
P

poolneophyte

0
LifeTime Supporter
Jul 1, 2009
275
Long Island, NY
When coating the grids of a DE filter on a system with a variable speed pump, is there a particular pump speed which must be used? I thought I read a post somewhere on this board stating that the grids will not coat correctly at lower speeds. I am asking this because I stripped apart my one year old filter at the beginning of this season and completely cleaned the grids. I then re-coated the grids using the total amount of DE required for a new filter but I think that I did it at a pretty low speed. I mentioned in one of my other posts that I have been trying to vacuum out fine silt but it is coming back to the pool in the returns. I don't remember having this problem last summer when the pool was new and was wondering if I did not coat the grids correctly.

So, what is the correct way to coat the grids using a VSP? Could this be the reason that the fine silt is not getting trapped in the filter?
 
You probably don't need to do it at fully speed but I would at least have about 15 PSI of filter pressure when you do coat the grids.
 
Could this be the reason that I can't vacuum up fine sand/silt without it returning back to the pool? From what I have read, a DE filter can filter to the 3-5 micron range. Shouldn't this be a high enough filtration rate to capture fine sand/silt?
 
Yes it should be able to filter that out so the problem could be that you have not coated the grids properly or perhaps not enough DE.
 
Actually, the most important thing when adding de is to have all the air bled out of the tank (de can't jump out of the water and pre coat dry grids). An increased pump speed will probably help with the pre coat. But not any faster than say 10-15 # on the filter.(like Mark said)
 
I called Jandy tech support today and spent approximately 80 minutes on hold (even though their message said a 20-25 minute wait) before giving up a leaving a voice mail. To my surprise, they called me back within a couple of hours. The support person that I spoke with said that the grids will coat properly at whatever speed you run the pump at. I believe the answers that I received from Mark and Pool Clown are correct and that the support person that I spoke with does not know the technical aspects of Jandy's products.

I will probably open the filter up again this weeked and do a complete cleaning and then recoat the grids at a faster pump speed using the total amount of DE required for a new or clean filter. Thanks again for the help.
 
This weekend, I opened the filter and completely cleaned the grids using a garden hose with a nozzle. I then re-started the pump and made sure that all air was bled from the filter before re-coating the grids. Per earlier recommendations, I used a higher speed (3200 RPM) when re-coating the grids. I also left the pump running for the rest of the day at 3200RPM so that the DE would stick to the grid.

I then tried brushing the silt towards the main drain but still can not remove it from the pool. I don't know if it's passing through the filter or if it gets suspended in the water (during brushing) and settles out when the pump is not running. I will try to use the vacuum head rather than brushing to prevent it from getting stirred up.
 

Enjoying this content?

Support TFP with a donation.

Give Support
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