I DIY'ed a top made from a plastic type cutting board, I found a black one,
I traced the top that came with unit, dremiled it to size, hole saw for hole's.
I went with 16 sites 2" plugs,
I wanted colored plugs so my labeling errors might decrease..& the org manf did not offer
color neo plugs
also used a glass drawer nob in center of top for handel
here are a couple pix, they are in use, one for heat mat table, have a few Dog OG & Fireballs started..
As for rez change, I normally don't need to as they root so fast, two wks then transplant,
no food, only H20 , very sml amt of Pro-teckt, & KLN
so I have added fresh as evaporation & use drop water level a bit,
I also threw in an air-stone
but it really is plug in & forget,
( I get better results when I DON'T F with it !!!)
here are a few pix,
BB