vacation advice

[pairustwo]

I've got a 20 gallon FW at home that has pretty heavy filtration on it A Fluval 204 and a HOB filter. It it also pretty heavily stocked -
4 neon tetras 1 inch
2 albino corys 1 inch
2 SAE 2 inches
2 Gourami 1 inch
1 Blue Ram 1 inch
1 Guppy 2 inches
1 Red Tailed Shark 2.5 inches
1 Zebra Pleco (Fake) 1.5 inches
1 Pit Bull Pleco 2 inches

Which is pushing the inch per gallon rule. The tank is clean never going above 5 ppm nitrates. I do a lot of water changes but the level doesn't seem to go up very quickly.

So I wonder: Can I add 8 tetras and 3 German Blue Rams (or angel rams) to this tank while I'm on vacation without poluting my tank? The extra fish are in my classroom and will be sealed in during spring break. I have a fish sitter who will feed each day at home.

Or should I get one of those vacation feeders? The last time I did that the fish ate each other instead of the feeder thing.

What do you think?

Pairustwo