Ebb & Flow Questions

For those of you running Ebb & Flow systems, how long does it take for your table to drain?

My table will fill (to where I need it) in 2 minutes and 40 seconds. It will drain all except maybe 1.5" in about the same time but that last 1.5 or so inches takes quite a while to drain. Will this be an issue?

Also I notice that most flood for a total of 15 minutes when they choose to flood. Is this by choice or are you flooding for an entire 15 minutes due to the analog timers restrictions(15 minute minimums). In other words, if you were using digital timers for your flood pump, would you still flood for 15 minutes or would you shorten this time?

Please let me know what size table you have. Mine is 3'x3'

Botanicare Tray Table 36" X 36" X 7"
2x 3/4" Botanicare Ebb & Flow Fitting (one for flood one for drain)
2x Botanicare Ebb & Flow Fitting Extension (for the drain height)
ActiveAqua 400 Gallon Per Hour Submersible Pump
Ecoair 3 Commercial Pump Air 65 liters a minute

Some people with digi timers still run for 15 min. It takes my pump 5 min. to fill my tray and I run for 7 min. I am not sure which way is best. It takes my tray longer to drain than it does to fill and I have the Botanicare trays, fittings and an Eco air commercial 5.

Mine takes 00:04:40 to fill and 00:7:00 minutes to drain. My timer runs for 5 minutes. I see no reason to run it longer than it takes to get to the fill line you desire. It has done it's job and prolonging it is just bit more stress on the roots than needed. Unless you have a medium that takes longer to properly wet such as only rockwool and you're waiting for it to wick up enough water to feed your plants but not drown then just start the drain when it fills.

Why does the last 1.5" take so long to drain? Are you using a hydro ebb/flow specific fitting or is it a diy that is causing it to drain slower at the end?

I'm just using the fittings the store gave me. I'll try shortening my lines up a bit. Maybe they are too long and it's hard for the water to flow through

Hm, length shouldn't matter as long as it is going down. Gravity/pressure does all the work. No kinks or loops or anything? A clog? Otherwise I can't imagine what would cause it to be so slow. DIY container bowing causing water to be under the drain filter? Picture would answer my thousand questions haha

The last 1.5 inch of water does not have near the head pressure that the first few inches had. It has to push the water through the pump backwards and into the rez. I don't see what the problem is, unless it is taking a prolonged amount of time here. Mine takes about 5 min to fill and 6 min to drain.

Goldowitz, your times are similar to mine but it was stated it is taking awhile to drain I guess if the res is well oxygenated it won't drown the concentration of roots that is sure to exist on the bottom if it isn't too much longer than 10-15 not much to worry about.