Please help me troubleshoot mold I have tried everything
This is my 4th attempt or so and I am still getting mold issues. Below is my entire process in as much detail as possible. There are also some attached pictures. I know most of it is root hair, but I do see some smalls stringy strands that go across the coir and look very much like the spider web mold that eventually develops. I zoomed in on these but my camera isn't the best. These pictures were taken after a slightly less than 48 hours germination period. I uncovered and took the pictures right away.
My process:
Sanitize trays - dish soap, hot water, hand scrub, rinse, dry on rack, spray with food safe 3% peroxide, dry again. Sprayed lightly with 3% peroxide right before use. The peroxide was introduced after the first couple of tries as an attempt at a remedy. The trays are 10x10, one with holes on top of one without holes, with the ridges lining up and sitting in each other.
Coir - hydrated right before use with tap water. Heavily squeezed and wrung out. Very little if any water comes out when squeezed. You would have to apply a very mighty grip to see water come out. Placed into trays, pressed slightly to even out the surface.
Sow - 10g broccoli, 20g radish. Started off just sprinkling it by hand, most recently used an old spice shaker to shake it on there. I spread out any clumps with my fingers after, but there are always groups of seeds here and there. I try not to let any sit on top of each other too much. I used to sow more heavily, but eased off in an attempt to combat the mold. The seeds themselves came from Amazon and are two different companies. Stored in their bag below the grow shelf. I seem to have more mold issues with the radish. I do not soak the seeds in any way and use it right out of the bag.
Germination - sometimes I spray the soil after sowing with peroxide. I've experimented with misting with just water after sowing, misting just a little bit of water, and misting with a tiny bit of peroxide. I can try not misting at all in a future attempt. I then stack another 10x10 tray on top. I have tried one with holes and without. I then put weights on top. Specifically 6-7 lbs of weight; they are bricks that I've wrapped in plastic for sanitation.
Germination pt 2 - they then sit on the shelf. During this period I have experimented with a USB fan on them vs no fan, misting them with water or peroxide in between vs just straight leaving them alone, checking on them and rotating the top tray for even pressure vs just leaving them alone, 2 days vs 3 days, and weighing them with a piece of wood in a zip loc bag for even weight distribution. They've come out of germination when the top tray is being pushed up, sometimes later, sometimes earlier.
After germination - when they come out, they go directly under Barrina T5 full spectrum 1 ft strips. There are 2 strips per rack, 1 per tray. The lights are about 6 inches above the trays. I have also tried 8 inches above the trays. 16 hours on.
I only bottom water. I have tried a lot of water, less water, and only enough water to fill the ridges. Have tried only watering in the morning when lights are on, watering less but 2 times a day. I have watered so little before that every morning they slumped a bit and the coir was dry. They then perked back up after watering.
USB fans are on 24/7 at this point. I've tried all the speed settings. Pointing them right at the tray, horizontal airflow just above the canopy, right across the canopy, and across at the stems. Fans have been barely making contact all the way up to the point of blowing some corners over.
I have tried misting on top with peroxide when I suspect mold, I have also tried just bottom watering and leaving them alone.
Environment - in the beginning humidity was very high; in the 70s RH. Temperature was also high, in the high 70s to low 80s. I have since bought a dehumidifier for the room, and humidity is now consistently 50-60% according to the dehumidifier. Most of the time it's at 45-50%. I also run the A/C more often; temperature is consistently 70-80.
The mold - in the beginning it only showed up after 2-4 days after germination, but I also probably didn't know what to look for then. It is always the stringy spider web mold. It pops up sparsely after germination and seems to continue to progressively develop (at a faster rate on the radish I've noticed, maybe?). I have tried misting with peroxide, removing it with tweezers, and ignoring it. The mold is always only at the bottom, mostly around clumps of ungerminated seeds or the one off dead/ungerminated seed here and there. When it gets really bad, it is a couple days before I would like to harvest and before true leaves are formed, causing me to harvest early.
I have harvested and eaten trays with a bit of mold; nothing has happened to me yet but obviously I would like to combat it entirely. I have had trays where I thought to myself "oh nice no mold whatsoever on this one, or at least extremely little" but there's got to be a way for a hobbyist to get 0 mold, no? Is there something I am doing wrong? Or is the mold/spore count in my apartment just too high to grow microgreens without some level of mold? I have included a picture of the trays on a day where I harvested. The greens grow beautifully aside from the mold.
PLEASE HELP