You have a little algae growing on the rockwool. Not a big deal in small amounts. You can control that by preventing light getting to it. The leaves look like they may have been wet for a while? Watch to make sure this does not spread. If the plants are big enough you can just prune them off.
OK. My plans with respect to the rockwool and algae, I have read that H2O2 is good for algae and have used it to some success in a small "ornamental" pond in my yard. I'll exacto-knive away the algae and apply drops of H2O2 to these areas. I will then cover the rockwool until each feeding.
Don't use H2O2. The spores for that algae are everywhere in your house,tent etc. and will just return if light is allowed to reach the moist surface. H2O2 will kill the very microbes we are trying to get established in your soil.
The largest is 3.5in wide and 2in tall, the other is 2.5in wide by 2.5in tall.
Ok get some white styrofoam plates and glue tinfoil between two of them cut to the center and make a whole big enough for the stem to grow but still shade the soil to prevent algae growth. If you need to you can cut the plates in two pieces and tape them back together to make it easier to get them under and around the plant. Watch the two leaves over the next couple of days to make sure that problem is not spreading or just cut them off.
I did get the water spikes and have tried them out. They seem to work. They are made of ceramic/plastic. Will buy some plates and do as you suggest. So, you want to make a double layer of Styrofoam with aluminum between them. What about a thicker disposable aluminum pie tin? I have to go find a water pressure control valve in town as Amazon's 2 Day shipping is going to take 7 days! I need to fix my boiler before I leave town.
The idea is to keep the aluminum away from the soil. Nutrients will leach aluminum into the soil and it is toxic to the plants in even small amounts. but sandwiched in between two styrofoam plates it will totally block the light and the white plates will reflect the light back up without hot spots that can burn the leaves from underneath.
The aluminum pie tins have the elevated edge and the edge that does touch the soil is dry and will be for some time.................but I do get the aluminum leaching and toxicity issues is a good enough excuse to "not take a chance."
