Flood and Drain Question

[jonb]

This is my first time using hydroponics and I have chosen the flood and drain system. I have four 4'x6' trays, two reservoirs (one for each pair), and two big pumps (one for each pair). I have my plants in 6" baskets filled with hydroton.

I recently transferred my rockwool cubes which I planted the seeds in into the hydroton. I was told to run the pumps for 5 minutes every hour. How high up on the baskets should the water be getting? When the trays fill, they only fill to about a half inch from the bottom of the baskets. This doesn't seem high enough to me, the little rockwool cubes are like 4" up, how will this water reach them?

I have been told that hydroton leaches the water up. Is the 0.5" up sufficient enough for the hydroton to leach water all the way up to the roots of these seedlings? Or should I be running the pumps longer?

[Greenbudz]

I would run the pumps a tad longer. If I recall flood and drain tables should have a overflow valve/stem. Ideally you would want the water level 3/4 up the sides of the pot and or to the level of overflow vavle/stem.. This is because as the water drains it vacums the old air around roots out pulling fresh air down and through roots. Sort of like a tub drain when it forms the vacuum whirl pull as the water drains down the pipe. Hope this helps good luck.

[jonb]

Okay I have it running for 8 minutes now. The table fills to the overflow (about 3/4 up the baskets). Hopefully this will save my smaller ones which seem to be dying.

[dank daddy]

that seems like a bit too often to be running flooding your tray.
You may in fact be overwatering them which is why the smaller ones are dying.
I run an ebb and flow system and would flood it every 6 hours for about 15 minutes. The hydroton will stay moist enough for the plants to flourish.
Also do you have anything on the botton of the baskets to prevent the roots from growing everywhere in your tray?
if not you might want to add hydroton around the baskets too so the light wont kill the roots.

[jonb]

Hmm, only 4 times a day then. The reason I have it running every hour (only twice during the 6 night hours) is because the hydro shop I bought it at told me to that.

No I don't have anything at the bottom of the basket. I was told to trim the roots. First when a few long ones start coming out, cut those off. Then the plant will be forced to expand its other roots to get water instead of relying on those inefficient long ones. This way the plant will have a more even, stronger system. The second time you trim and will force the plants roots to stay compact so transporting between trays would be no problem (i.e. roots don't go all over the table).

[Greenbudz]

Yes you most definately can trim roots. We do it at the greenhouses I work at, we call it scoring the roots , our crops are all soil based. I wouldn't trim up thick roots but the smaller ones the secondary off main roots can be trimmed forcing more stronger roots. I would limit the number of times this is done though. And wouldnt trim in flowering stages.

[ocitown]

The roots MUST get water,whether in the HT or out but if not they will die.

Once you see roots below the pots your level wont need to ever touch the HT cause the roots will be in the solution.

Small plants at that stage sometimes need a little help by just adding water over the HT 1-3 times a day.

Floods need only be done when lights are on too.

[Mothers Nature]

Hey JonB...I just ordered the exact sime size in ebb and flow trays and was wondering how to set up my lighting scheme...4 X 600w....2 X 1000w..5 X 400w etc...what do you have above your ladies?

MN

[ocitown]

Originally Posted by Mothers Nature

Hey JonB...I just ordered the exact sime size in ebb and flow trays and was wondering how to set up my lighting scheme...4 X 600w....2 X 1000w..5 X 400w etc...what do you have above your ladies?

MN

I would say that may depend on how you arrange the trays,you have the same size and four of them?

If theyre all lined up,more lights may be better but in a large rectangle i would say a 600 under each would be best unless you plan to grow taller plants then the 1Ks would be my choice.

600W systems IIRC have a better conversion for power to lumens but they also have more limited bulb choices and some "E" ballasts wont work with HPS and MH.

[jonb]

Thanks for all the replies.

ocitown, I have the flood going twice during the dark. Though this may be pointless because they aren't leaching through their roots at this time. Can it hurt though? Thanks for the tip about the smaller ones, I'll try that hopefully it's not too late.

As for dank daddy's comment about only running the pumps every six hours, do the rest of you guys agree or do you think it is okay for me to be running every hour during light.

Mothers Nature, I have two 4'x6' beds in my veg room and the other two my flowering room. So for my veg room I have two 200W compact fluorescents over each bed. For my flowering room I have two 600W high pressure sodiums (with digital ballasts) over each bed. And for all of my lights I have pebbled metal bat-wing reflectors.

Also, in the future I want to add some T8 fluorescents around the beds, to give light to some leaves that you might lose otherwise.

[ashesfrombuds]

no way should you flood every hour.... I would say every 4-5 hours during the beginning until your plant gets established with at least 4 nodes, and then cut the water to a maximum of 4 times per day..... Also remember that the bigger your rockwool cubes are, the more water they will hold, and you will need to water them less.... Id go with a 4X4 cube. they retain shit tons of water.