DIY Aquarium pieces?

[HP12300]

So I'm starting to set up my aquarium for my future Axies, but I was wondering if anyone had any experience in making their own aquarium decorations. I wanted to make a couple different hides and a shelf or two. I found a couple of people who've made things from sculpey, and painted them with standard acrylic paint, which I know is fish safe, but would it be safe for Axies?

After the tank is done cycling, I'll probably throw some in there and test all the levels anyway, but it'd be time saving if someone else with experience could give me some tips before I dive in.

I wanted a couple of wall hides where you can see into the hide from the side of the tank, sort of like in reptile tanks, so I also was wondering what sort of sealants wouldn't be toxic, so I can put magnets in them.

 

[Colecago]

I'm also very interested. I have a 3D printer and want to design and print some decorations. I've read so far that the most important part is to use non-colored filament so the nasty dyes won't leach into the aquarium. That leaves me with white or clear, so any suggestions on painting and sealing would be great.