Why do you bottom water seedlings? I had this conversation offline with someone else this week. Surely seedlings don't have the root structure to dry out the bottom of the pot leaving uneven moisture content in the compost.
It's a curious thing to do with seedlings. Same situation arises when top watering plants though. Bottom watering rewards the lower root system which then grows larger down low, whereas plants that are frequently top watered can have trouble utilizing deep roots due to poor aeration resulting from the "top heavy" root system. Ideally you want an even root system, which bottom and top in combination easily facilitate.
I have used fabric pots, bottom watering turned their lowest roots into jello. They don't air prune properly on the best days in my experience, throw it out the window when bottom watering.
filedata/fetch?id=17824260&d=1617206795 Bottom watered here, by wicking up from wet perlite. 7 gallon soil. The perlite was in contact with the bag there.
Finally got a minute to put it up. Soon will install the fan and filter then hang my marshydro tsw2000