Thanks everyone 😀 I have thought about evening lighting, but I only really thought about lighting it from above...only because I didnt know of another method, and I wish I had seen these messages yesterday and I wouldnt have been so hasty to spray them black so I could fill them! So I guess i'm stuck with lighting from above as there isn't room behind to scrape it off. I filled the larger tank earlier and despite washing the sand countless times its still a cloudy mess right now, hopefully by the morning it'll be clearer, although I haven't finished my DIY large filter so I'm only using the small filter for now.
As for decor, I'm set on a river look for the larger one, I have some large pieces of driftwood and huge river stones in there now, but even with a month of soaking they are still boyant so I've got a rock on top weighing them down until they are fully waterlogged, I still need to get a bunch of smaller pebbles to make it look more natural. But as far as the smaller tank goes I haven't made a final decision yet, I'll be using the same sand but I think I'll use different plants for some contrast (maybe just a moss and pygmy chain sword tank), I'll try and get more pebbles than I need so I have some spare for options.
I'll try and get a photo up tomorrow if it's clear, but bare in mind the wood is being weighed down so the scape is far from complete!