Ebb and Flow tray keeps flooding my grow room? HELP

[Gstone]

I just set up one of my 4x8's yesterday and it keeps overflowing 20 or 30 gallons onto my grow room floor. Luckily I have pond liner down but this is still beginning to be a real pain in the ass. I have set the overflow fitting down to its lowest setting and it still does it. Right now the timer is set to flood for 15 minutes every 4 hours. I am using 6x6 rockwool cubes. The pump I have is an 800 gph hydrofarm in a 100 gallon reservoir. Should I get a digital timer and only flood for a certain amount of time? Any help would be appreciated.
Thanks

 

[Tr33]

What are the sizes of your fill and drain tubes?
Your drain tubes MUST be larger than the fill tubes!!!

I use 1/2" fill and 1" drains
never a flood, ever.

 

[Gstone]

O that could explain it they are both 3/4

 

[FreezerBoy]

Mine were the same size but, I used twin drains for one fill tube.

 

[paladin420]

Are you stil sucking water thru your pump. You must break suction. Good luck

 

[LittleAmsterdam]

Several comments....
1. You're flooding a lot of water for a 4X8 to overflow by 20-30 gallons. You need better controls / timers to pump for less time
2. Your pump must be a BIG ass pump to pump that much water and still overflow your overflow drain

I use a small pump on a timer for 7min. every 3-4 hours. I pump approximately 10gallons into a 4X4 and NEVER rely on the overflow !

 

[LittleAmsterdam]

Ahhhh.... Are you using a barrel to hold the 100gallons? If so you have a siphon issue and need to fix that.

Ebb Flo reservoirs are intended to be below the table so you don't have this issue.

 

[Yes4Prop215]

no rocket science here...TURN THE PUMP OFF!! set your timers to less than 15 minutes...it only takes 5 minutes to flood a 4x8 tops...and you should have your overflow tube that would drain everything out even if it did flood. 800 GPH is way too much i use 250gphs on my 4x4s so i would use a 550 for the 4x8...


common sense use gravity...the flood table is not gonna drain if your reservoir is higher than the table...the res needs to be below the table..

 

[paladin420]

Ahhhh.... Are you using a barrel to hold the 100gallons? If so you have a siphon issue and need to fix that.

Ebb Flo reservoirs are intended to be below the table so you don't have this issue.

"siphon" thats the word thanks

 

[LittleAmsterdam]

Where's your reservoir?

 

[Gstone]

Whoa hold on now. My rez is inches below my table, the overflow is allowed to fall directly back into the rez. I think the thing to do in my situation would be to ditch the crappy hydrofarm timer that only allows me a minimum of 15 minute flood time for a digital one. Correct me if I'm wrong..... Please

 

[High Country]

I'm with Tr33, there has to be more water coming out than what is going in. I also have a larger drain fitting than the inflow and have never had problems. If that doesn't work you may have to get a smaller pump. It may just be putting in way to much water than the drain can handle.

After very heavy rains some road drainage cannot get the water away quickly enough. There is simply to much water for the diameter of the drain to handle and then we have overflow.

 

[LittleAmsterdam]

OK, the res is in the proper location.... Your pump is over powering your overflow.

Buy a smaller pump and raise your overflow to the level you would like to flood to. Like I said I never use / rely on the overflow. I have a smaller pump and a digital timer.

 

[mesh99]

Hey mate, troubles with the system? I cant rem. your set up. Are you using a bell siphon?

 

[LittleAmsterdam]

I have set the overflow fitting down to its lowest setting and it still does it.

The overflow is supposed to be higher than the fill. It serves two purposes.
a. keeps the water in the table a little longer while it's draining through the fill hose
b. safety measure, but NOT supposed to be used ! If you are then you're filling too much for too long and not using the overflow correctly.

 

[mesh99]

Ok, just sussed out your set up and you don't use a bell siphon. Have you ever used one?
Once you get it dialled in the system just floods and drains by itself while the pump just trickles in water 24 hrs a day. You can get away with using a tiny pump and no timer.
My setup uses a bell siphon made out of a couple of 19mm fittings and a small piece of PVC.

Just from the design, this system will not overflow.

Ayway....just a suggestion.

 

[Gstone]

I'm not sure what a bell siphon is, so no I don't think I'm using one of those.

Thanks for the help everyone, a larger overflow and a digital timer are now on my immediate shopping list.

 

[supersmallgiant]

I'm not sure what a bell siphon is, so no I don't think I'm using one of those.

Thanks for the help everyone, a larger overflow and a digital timer are now on my immediate shopping list.

I don't think a new timer is needed. When ebb and flow tables are set up correctly they will never flood even if the pump was left on infinitely. I have good luck using 1/2" fill with 3/4" drain with my 396gph pumps. One problem I ran across that caused me flooding was having my drain extend down into the water in the reservoir. When the water would rush into the drain it would trap air between the water in the reservoir and the water rushing into the drain and hydrolock the drain. Triming the hose so that it doesn't hit the water in the reservoir completely resolved this. The second reason I have seen flooding is having roots grow into the drain. I now use smart pots in the table to resolve that.

Fix your tables... don't band-aid it with a different timer. If the timer ever fails-on, you will be flooding your room again and wishing you had fixed it right.

 

[LittleAmsterdam]

I see people making comments about a FILL and a separate DRAIN. NO that's not correct.

The FILL is the DRAIN and the OVERFLOW is a safety measure to prevent floods. The OVERFLOW is set soo high the water would never drain through it unless it was spilling over into it. Like I said before you're not supposed to use the OVERFLOW, but have better control with a smaller pump and a digital timer.

Research more how to correctly setup Ebb & Flow tables, specifically the OVERFLOW and you shouldn't have these problems anymore.......

 

[LittleAmsterdam]

I also use 1/2" fill with a 3/4" drain and 250GPM pump. I flood every 4 hours for 5-6min and allow the water to drain back through the fill house and never rely on the overflow.