Old tank, new build?

Hey guys.. I've been thinking.. I have a 20 something gallón tank in my garage.. I was thinking that the clowns I have in my 150 are a bit to boring for it since there aren't any corals and the black ans white doesn't really help the color thing...

So I thought, maybe tomorrow I could do a water change to my 150g tank, and fill my 20g with that water, and transfer the clowns to it for my room. I could take some sand and some rocks out of my 150g. And I have a spare powerhead and a mechanical filter rated for a 20-30g. ( I could get a bigger later on. And since it's summer water stay pretty much at 74-78 degrees. But I could get a heater too later on)
would this woRk?
I kind of wanted some more colorfull clowns for my 150g.. Maybe some percula or some tomato clowns...
I thought about just returning my clowns to the lfs but Idk I feel a bad feeling in my stomach to just give them away after 6months with me..


Ps I forgot to mention that I used that tank for a QT long ago when I got ich and I used a copper safe solution on it...
Does that mean I can't put any inverts in there? Or can I just wash it real good?

 

if i read your signature properly you're also in the midst of a 29G build. so in the end you'll be maintaining 3 tanks.

so long as you've figured all your maintenance costs out, id say go for it if you can sustain another tank on your pocketbook

 

I only plan on keeping those 2 clowns in there. Because I don't really wanna get rid of them. And pretty much I have everything I Need so cost isn't really an issue.

How about the inverts? Will they be ok? ( by inverts I mean snails ans maybe a cleaner shrimp)