Algae on soil?

One is dry. One is wet. One is too wet (algae is a sign of frequent over-watering).

I would say your pots are drying at different rates either due to minor inconsistencies in your perlite ratios between the different pots or more likely airflow differences in different regions of your tent. Is the one by your air intake the "white" one and the one furthest away the green? Do your pots stay in the same place or do you rotate their positions?

Algae grows in wet environments that are bathed in light. You top feed, therefore you fill the top of the light exposed soil with food, water, and light. Everything algae need to grow. To combat that, you can either cultivate the top inch of your soil with a fork after you water to fluff it up which will agitate the soil and the algae spores, allow for air to get down to the root ball better, and fluffy airy soil dries out faster which makes it impossible for algae to grow. The other solution is to bottom water your plants. Then you get the perfect distribution of water and nutrients in your soil, and the top inch of your soil is always fluffy and bone dry. No algae growth, no mushroom growth, no fungus gnats, no bullshit. I leave it to you to choose your method.

Different amounts of water is my guess, from to much to little and just right. Goldilocks of sorts. The one growing alge or moss is most likely a bit to wet, the one that looks "normal" no green or white is probably perfect, and the one that is white is likely mineral depots. Could also be mold but doubt it. Just confirm you are getting good runoff to avoid the mineral depots and the alge won't go away, you can scoop it out or mix it deeper in, it need light to live so remove that aspect and it will snuff its self out. Good Luck!