Puffer Fish Tank Essentials

[kit-kat]

I have two GSP in a tank with generic gravel and plastic plants and I'm looking to re-do it in a more healthy and more aesthetic way. I'm a college student, read: broke, limited space, and moving across the US in 6 months and counting for grad school.

They're in a too small 5 gallon hex tank right now (got them essentially from an irresponsible ex-roommate, long story). They are under 2", healthy, happy, haven't had dark bellies/sides since they were very sick after coming home from petco. I have them at mid-BW, but would ultimately like to convert them to SW soon since they brightest/most active I've ever seen them was when their tank was accidentally a .002-.003 higher than I'd intended. And since in another thread they talked about it improving their health and increasing their growth rate.

So I have a few questions.

Part 1: I happen to have a 15/20 gallon tank I could steal from my parents that I could put them in but I'd hate to move the little buggers for a few months, and then have to traumatize them again for the move. Which I plan on doing in their hex tank, half full, no decorations, and some sort of battery powered aeration system that I haven't yet fully decided on. Should I just move them to the bigger tank, or hold off since they're so small and are healthy. Should I convert them to SW now, or wait until I move?

Part 2: Decorations. I was thinking of trying Java Moss, but would rather not if I just going to convert them to SW soon. I'm going to switch them to aragonite sand as soon as I get my hands on some black/dark stuff (there's nothing wrong with dark substrate for them is there?). I could keep the plastic plants/get more. Or I could convert to SW and try some SW plants. Or I could keep them BW and get java moss/java ferns/etc. I'm also interested in getting some lava rock, I would think this would help with good bacteria and such/look pretty.

What do you guys think?

[Pufferpunk]

Absolutely move them to a bigger tank. They won't last long in a 5g--no matter how you try, there will never be enough surface area for enough nitrifying bacteria to colonize on to support those heavy waste-producing fish in a 5g.

Dark substrate=dark fish.

[ProPuffyFish]

I jut recently set up my own puffer tank so I'm not an expert but I'd move them into the 15/20 gal as soon as you can but keep the 5gal going so it'll still be ready for the move, just make sure the temperatures and salt amount are the same and the puffers wont notice the difference while they are on their way home.

Also since they are still so little just convert them to brackish water for now until they are adults and remember cycling the new tank will take about 2 weeks, dont just fill it and throw them in lol though I dont think you would have. Best thing to cycle the new tank is to use some of the gravel from the old tank and put it in some nylons and leave it in the new tank.
Hair grass and anubias also do well in brackish tanks. Java moss looks great when grown on lava rock so good idea. Also I've heard darker gravel makes the GSP green colours stand out more.

[Pufferpunk]

I would fill the tanks with all the substrate, decor, water & filtration material from the smaller tank & transfer the puffers over to the larger one, ASAP.