I have a 48sqft Hayward DE filter that I was told on this forum is too small, but I'm keeping it for now since it is only 4 years old. Previous owner used Leslie's brand cellulose instead of DE and I have been doing the same. Recently, I have been having to backflush every 1-2 weeks as the pressure rises from 22 to 28 psi in that time. When it gets to 30-31psi I can't even vacuum my pool.
Since I don't know how long it has been since the last manual cleaning, I took it apart this weekend and cleaned it after doing a few backflush/rinse cycles. I found a lot of clumping of the celluse material which I have heard people complain about. I think it was my fault as I was dumping the stuff in the skimmer instead of making sure it mixes well first.
After my manual cleaning (but no chemical cleaning) the filter pressure was 20psi w/o any cellulose and barely rose after adding cellulose very slowly to the skimmer.
A few questions, then some photos
1) Do these grid photos look normal? You can see some clumping of material where the backflush was not able to get it all out. One photo shows algae on part of the grid, this was pretty common with all the grids I cleaned.
2) After a manual cleaning, do I need to fill the lower half of the filter up with water before closing it up and starting the pump? Any other procedure I should do when starting up again?
3) I tried to do the test to see if I needed to chemically clean but wasn't sure how to do it. Do I pour water in through the inlet to a grid and see how long it takes to disperse? Or do I just spray water from the outside of the grid? I actually had a hard time getting water into the grid just from the outside. We have very hard water so I imagine I have a lot of build up.
4) What can I safely use to do the manual cleaning? Is a brush OK? I had a hard time getting the algae off with just a stream of water so I'd rub them down with my hands.
5) Is it better to just keep the grid array all together for manual and chemical cleaning? I thought dumping that whole array in a bath of MA sounds like a lot of MA, do people pull all the grids out and lay them down on each in a bath instead?
Thanks for any advice.