55g Dsm/walstad Tank: Month 1

Month 1: So far I have the tank, painted the rims and the back/side panel black to increase the depth. Have my DHG and lighting ordered (plan on getting s repens as well), went a little overkill on my substrate so I'll just be using what i haven't already on another tank or for the emerged plants. I'm currently in the process of moving so I won't be able to set up my tank until then but I've been tweaking some of my ideas since I'm really not in a rush to get this done.

>I was thinking of adding maybe a .5in of gravel so the soil doesn't go completely anaerobic
Top soil
Another .5in layer of gravel, then the sand because its coarse grained,
Once it's filled and cycled i was going to add trumpet snails/stuff that likes to dig to keep the soil/sand aerated and i feel like doing the two gravel layers should help with that
(basically gravel layer top soil gravel layer sand gravel sand)


>With this walstad tank I'm not planning on running a filter for flow like i did on my 10g, just one or two powerheads maybe 240gph-300gph on both sides of the tank, I want this to have a steady/moderate flow, I'm feeling that two should do the trick, feel free to give me advice on this

 

Slightly dumb question but here we go, how do I keep the sand from flying/floating up when I'm filling the aquarium?