What size res. do I need for a 4x4 flood table?

[keylime]

I have 2 4x4 flood tables and two 30gallon res. The guy at the hydro store told me that 30gal. res. was enough to fill the table and when I ran the pump it only filled up to half way up the table and the pump started to run dry. So im guessing I need a bigger res. Also, it takes about 5min to fill up the table half way.. and 10-15min to drain. Is thier timers that turn on for 5min. and off for several hours?? I have a 3on/off timer but It cant be turned on for less than 30min. So what timer should I use?? THanx for reading

I have two 4x4 trays and two 30 gal res and never had a problem. You need an overflow on your tray, maybe 3/4" pvc pipe, it needs to be adjustable to the exact height you want the nutes to come up to. When the level comes up to your designated height, the water will flow straight down into the res again through the overflow. I run mine every 4hrs for 15 minutes, using a timer.
keylime

keylime Reviewed by keylime on 12-20-2010. What size res. do I need for a 4x4 flood table? I have 2 4x4 flood tables and two 30gallon res. The guy at the hydro store told me that 30gal. res. was enough to fill the table and when I ran the pump it only filled up to half way up the table and the pump started to run dry. So im guessing I need a bigger res. Also, it takes about 5min to fill up the table half way.. and 10-15min to drain. Is thier timers that turn on for 5min. and off for several hours?? I have a 3on/off timer but It cant be turned on for less than 30min. So what timer Rating: 5