I have an 11 yo Fleck 5600 SXT AIO set to 7 gpm backwash flow on a 10 x 54 tank with an unknown media that was failing to remove iron and replaced the media with 1.5 cf of Katalox and 15 lbs of 1/8 -1/4 gravel. The system was very dirt with iron and sediment and the 5600 required cleaning to restore correct function and had low (5.6 to 6 gpm) backflow drain issues. Some of this was worked with Bannerman in another thread.
Today I removed the DLFC retainer and removed the flow washer but it did not appear to be marked so the 7 gpm sticker on the 5600 could not be confirmed. The flow washer had an ID of 0.27” and the DLFC retainer had an ID of 0.31 so I got another rubber washer of the same OD and drilled the ID to 0.30 (5/16) and retested. Got 7.15 gpm at 50 psi and 6.0 gpm at the pump 36 psi cut-in pressure. I then removed the modified flow control washer and DLFC retainer and got 7.9 gpm at 55 psi, 7.5 at 50 psi, 6.7 at 40 psi and 6.5 gpm at the 36 psi cut-in pressure so significantly to the 8 gpm you should have to prevent longer term problems. I intend to leave the flow washer and DLFC retainer out and would appreciate comments if there is any downside to doing this. Also is this an acceptable backflow rate for BW=14 and DO = 2, can drop DO to daily if needed. Iron level is 4ppm and daily water usage averages 100 gallons per day.
Secondly, another post suggested shinning a strong light through your tank to determine the top of the media and the remaining free space. My tank is 10” x 54” with the base. The gravel and 1.5 cf of Katalox is at 41” above the base giving 13 “ of free space. I was wondering if this is enough free space and if I should remove some media (shop vac ?) or just let some media escape through drain line during BW etc. Is there a downside to just letting some escape in the BW and letting the system find its own level?
Today I removed the DLFC retainer and removed the flow washer but it did not appear to be marked so the 7 gpm sticker on the 5600 could not be confirmed. The flow washer had an ID of 0.27” and the DLFC retainer had an ID of 0.31 so I got another rubber washer of the same OD and drilled the ID to 0.30 (5/16) and retested. Got 7.15 gpm at 50 psi and 6.0 gpm at the pump 36 psi cut-in pressure. I then removed the modified flow control washer and DLFC retainer and got 7.9 gpm at 55 psi, 7.5 at 50 psi, 6.7 at 40 psi and 6.5 gpm at the 36 psi cut-in pressure so significantly to the 8 gpm you should have to prevent longer term problems. I intend to leave the flow washer and DLFC retainer out and would appreciate comments if there is any downside to doing this. Also is this an acceptable backflow rate for BW=14 and DO = 2, can drop DO to daily if needed. Iron level is 4ppm and daily water usage averages 100 gallons per day.
Secondly, another post suggested shinning a strong light through your tank to determine the top of the media and the remaining free space. My tank is 10” x 54” with the base. The gravel and 1.5 cf of Katalox is at 41” above the base giving 13 “ of free space. I was wondering if this is enough free space and if I should remove some media (shop vac ?) or just let some media escape through drain line during BW etc. Is there a downside to just letting some escape in the BW and letting the system find its own level?
