Flood and Drain (to waste) 6 inch Rockwool for Commercial Scale Veg? (220 plants)

Instead of putting 220 drip emitters into the rockwool for veg (which I am doing for flowering) wouldn't it be smart to do "flood and drain" (to waste) for those 220 six inch rockwool cubes?

This can help me to avoid installing and maintaining all the dripper lines.

Is it a good idea?

Flood and drain to waste, won’t you be going through a crazy amount of nutes?

well I would just be flooding 8 sqm of trays (about about 32 sqm) to feed 220 cubes. they'd be packed in there pretty tight and would only need flooding i think once per 2-3 days or so?

Overgrowtho said:

well I would just be flooding 8 sqm of trays (about about 32 sqm) to feed 220 cubes. they'd be packed in there pretty tight and would only need flooding i think once per 2-3 days or so?

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honestly in veg just make sure too let the rockwool cubes dry out enough before flooding them again when their roots are small because no one likes wet feet. also i always assumed it was best too top feed because of salt buildup. but honestly i don't see why it wouldn't work. but im a scrub so hopefully someone with more experience can chime in.

You're going to want to flush them once every week or so with RO water if you do flood and drain. I would recommend running Coco mats underneath to encourage root growth.

When you get into veg and flower, you're going to want to flood more than once ever few days. You want rockwool to dry back to moist, never dry, because that causes Salt build up, PH swings in the cube, and other issues. I flood these girls every 6 hours, as I have for 5 weeks, and they're not very big plants. Mind you, I'm using 4 inch cubes, but the principle remains consistent.

The pictures are a few weeks old, the roots are even more dense now. I'm going to trim them back this weekend.

Those look super healthy and with fantastic roots! How do the coco mats encourage root growth? Would you recommend using them with drip emitters too?

I am now thinking to avoid the flood and drain (to waste) to save nutrients I suppose, actually we need to hand water for a while until we get the drip emitters going....

Therefore I started a related threat, please chime in if you can:

How to water clones in 6 inch rockwool cubes please?

How often and how much should I water clones transplanted into 6 inch cubes? How much runoff? How often to flush with r.o. (needed)? Dry back should be until moist how often? What PPM schedule should I use? Any recommended additives such as h202? Any other tips greatly appreciated! Note...

www.rollitup.org

Overgrowtho said:

Those look super healthy and with fantastic roots! How do the coco mats encourage root growth? Would you recommend using them with drip emitters too?

I am now thinking to avoid the flood and drain (to waste) to save nutrients I suppose, actually we need to hand water for a while until we get the drip emitters going....

Therefore I started a related threat, please chime in if you can:

How to water clones in 6 inch rockwool cubes please?

How often and how much should I water clones transplanted into 6 inch cubes? How much runoff? How often to flush with r.o. (needed)? Dry back should be until moist how often? What PPM schedule should I use? Any recommended additives such as h202? Any other tips greatly appreciated! Note...

www.rollitup.org

Click to expand...

I can't give the exact science, but it gets wet without holding moisture, so the roots will chase the water using the coco mat as scaffolding. I also cover my flood tray to keep the root area humid and dark

Overgrowtho said:

Instead of putting 220 drip emitters into the rockwool for veg (which I am doing for flowering) wouldn't it be smart to do "flood and drain" (to waste) for those 220 six inch rockwool cubes?

This can help me to avoid installing and maintaining all the dripper lines.

Is it a good idea?

Click to expand...

Iv done something similar, but its not going to be practical doing drain to waste, nor cost effective as you will be dumping masive amounts of nutrients for no reason as to cause the flood you wont be flooding with the exact amounts of water to re saturate the blocks only. Your best off recycling the feed. The way I used to do it was in veg the blocks would be flooded once a day to start. When they get abit established I would do 3 times a day in veg. The floods would push all the way through the blocks to the top so that all stale air and water and nutrients would be pushed out. When the flood declines fresh air is drawn back in. If you dont mess around with the blocks and squeeze them to alter the structure they at maximum saturation are designed to hold the right air to water ratio. But I also used to use h2o2 in my reservoir and would keep them highly oxygenated and agitated by having separate pumps running 24/7 with a pipe atached that wat come out about 6-12inches above the reservoir water line so that water fountains were always on the go in the holding reservoirs. The regular flooding and draining of the blocks with fresh air and feed from bottom to top with highly oxygenated water would keep them flushed and clean, rebalance any used up more or less than other elements in the blocks and keep the ph highly stable. But to do that often flooding and draining of blocks the size I did and what your using the water must be highly oxygenated. I think those size blocks can hold 1 and ahalf - 2ltrs (may be more I cant remember) of water a block, doing 200 pluss pluss enough water to completely flood all the way around and to the top you are going to be dumping way way too much water and mega amounts of feed. If you want to dump the water your better off using the drip spikes and do drip feed.

You could also look into nutrient film technique (NFT)

It involves a constant microfilm of feed flowing along the bottom of the tray. It's a half way between drip and F&D