EBB and FLOW with rockwool

[rimbaegeus]

Hi guys, I need some help. I'm growing in a 2' x 4' planter with drainage at the two opposite ends lengthwise. I currently have 15 plants in a mix of 4" and 4" x 4" x 2.5" rockwool blocks, with a flat of seedlings under a tent. I am planning to increase to at least 40 plants, with a soft cap probably around 65. I am toying with the notion of putting these plants onto rockwool slabs. I would like to stay with rockwool, as this allows me to remove only the ones I want flower. I have very briefly mused over pots, but have pretty much dismissed the option due to the extra cost of pots and grow media, although it would make things very modular. I first attempted a drip system, but encountered some issues:

1. I have too many plants for a drip irrigation system, as the planter quickly becomes a mess of hoses.

2. The vinyl hosing is not very plyable.

3. I experienced a high amount of leakage between hoses

As such, I am thinking of switching over to Ebb and Flow.

Would the water level need to reach the surface of the rockwool?

How do I take into account all the increased evaporation?

Can I do this without any other grow media besides rockwool blocks?

Thanks.

[Cornelius]

i think ebb and flow is definitely your best bet for that number of plants.

the water should wet the rockwool. If you let the water sit for a few minutes the rockwool will wick the water up, so you probably don't have to let the water get that high (though i bet you can if you want).

evaporation: i guess just keep adding more water, or put a cover over your tray.

rockwool: i'm pretty sure this is all you need, though make sure you don't soak it too much. rockwool holds more water than most hydroponic media, so you can ebb and flow less often

[rimbaegeus]

Thanks for the swift response. I have been running the lights from 6AM until midnight, and I have had the plants on a flood schedule of 3 times a day for 15 minutes at 6 AM, noon, and 6 PM. Too much? Should I cut it down to twice a day?

Thanks