These cubes don't really seem to drip dry so i'm a little confused by that. They hold a ton of water without dripping. I have to do this 72 times over and will have to dump and refill the bucket each time. I don't know if it's feasible to double soak all these cubes. Maybe a heavy top feeding of 5.5PH 600ppm nutes will be sufficient.
I just drew a syringe of liquid from one of the cubes, the PH was 6.3 so it doesn't seem like PH is a huge issue. Obviously want it down a bit around 5.6-6.0. They are looking a little better today than yesterday.
I'm also starting to get a bit of green algae appear on the top of the cubes. Recommendations to get rid of it?
When I said drip dry I just meant u till it stops dripping, your just trying to replace what's in there with your solution, a heavy/frequent top feed will work, one watering won't work. In a recirculating system it takes a couple hours for everything to adjust and level out so probably a day or two in your situation. More is better
A tiny bit of green Algee won't hurt anything, and that's all you can really do is cover the blocks like you have done. Scrape it off if it bothers you
6.3ph puts you out of range for some nutrients but no it's not that bad IF that was your only problem but you have a combo of things going on so it's certainly contributing to the problem
Those girls aren't looking great but they can still make a comeback if babied.
You don't have a feed system for 72 plants? What's your game plan here moving forward? Were you just gonna hand water these every day and check runnoff every day?
Method187
Just stop. Stop watering, feeding, watering, foliar feeding.
FOR THE LOVE OF GOD let your r/w dry out till they are VERY LIGHT (a tenth of their soaked weight say) or the plants start to get thirsty (soon as you see any wilting)
Then water,( don't spay them)
Method, what ever course you take keep the inside of the cube stabilized. And do not wait for it to dry out because it will literally take 2 -3 weeks. If you want the cube dry use a moist cube or paper towel to draw the water from the cube and continue with normal feedings. It seems most people answering here are giving advise for a healthy plant.
Packer also gave some good advise, it may not be what you wanted to hear but it's good advise and something to think about. The guy was good enough to take the time to write it so it's worth reading, that's how we all learn. But you do have two ways to fix your problem here and I'm sure both will work well for you so just remember to keep the cube stable, doesn't matter how you acomplish it, as long as you do.
Yes the leaves can get crispy when overwatered or nutrients are locked up. The stoma shuts and production has come to a halt.
I only reacted to what he said the way I did because it just isn't on topic for the thread and telling me to use soil or coco offers no help or solution to my current situation. I appreciate people giving their 2 cents but I see people all the time just bashing a different growing method because it isn't what they use. Every medium/technique has it's horror stories and drawbacks. I have grown in soil several times. It's much easier but I want to learn how to grow in rw/hydro because I have a long term plan/setup in mind using this technique. The only way to learn is to try, make mistakes and build knowledge. This community is a great resource but it annoys me when people just drop into threads and say 'see, this is why I swear by coco/soil/dwc/nft/etc.
The issue with trying to wick out moisture is it doesn't make much difference at all. I'd say these cubes are retaining 750ml-1L of water. Some paper towel isn't going to make a dent in that. Putting another moist cube underneath helps for sure, but I don't have nearly 72 extra cubes laying around and once they absorb the moisture from one of my active growing cubes, they are soaked and can maybe do 1 more cube before they have to be left to dry for a week. It just isn't feasible.
The only thing that seemed to work a bit was slinging the water out of them gently. It's what i'll have to do if these retain moisture for too long again.
The plants look much better today so i'm on the road to recovery. I think i've identified what caused this mess in the first place so I should be able to baby them back to health now.