Oh, ok - so it's two separate tanks then? The two plecs in that smaller tank pic - are they now in this larger tank? Hope so!
Anyway, good for you for thinking ahead about rehousing. I wouldn't add any more fish to your current set up, though. Just keep an eye on their sizes and when you see that they are nearing the 8-10" size then you can think about moving them out. At least you'll get to enjoy having them for a while, anyway. If the silver sharks are juvies at the moment, then the plecs will have been long gone by the time the sharks are grown.
All the best - Athena
