Need a pro for a ?

I have 3 4' x 4' trays im doing and ebb and flow i need to know how big of a Reservoir i need for a 4 x 4 foot. Also I only bought 2 600 wt hps and 2 400 wt lights will that be enough or should i just get 3 1000 wts I know i prolly wont need that much but the more the merry 'r also is BC nutes good for a hydroponic system ?

You need a 70 gal res. I run 4 by 4 also. I like 1000 over mine I have friends doing 600 over them, they seem to be just fine. are you going sog? what medium are you using?

sog .. 70 gallon per 1 right ?

70 isn't needed that is if you want to fully flood your table, but if your growing rockwool half flooding is only needed because rockwool obsorb all the water so i use a 30 gal bucket for mines found on walmart for 12 bucks.

The only way you'll know how much water needed is to fill it. Put everything that you are going to have in there, and fill it with measured water. For ebb&flo beds with room in between pots, you can use spacers so there's less nutrient required to fill. Put rocks, bricks, or plastic containers filled with water, anything that will displace space, but not mess up the nutrient, like wood or metal. Keep in mind that your res should be at least twice what you need to irrigate.

A 600w over each bed will give OK results, a 1Kw over each will grow da kine.

HTH

potroast knows what his talking about, i flood about 25-35 4x4 rockwool cube and a 30 gal does just fine for me but if you need it to flood higher you can always put something in it to have the water level higher. What i did in the pass was fill up 1gal and just place it on the table and i can get my flood lvl to where i want it to be.