Couple of cory questions

[Ava]

Hey all I'm thinking of adding some cory's into my new tank. We are cycled and ready to go. It's 20g and I'm planning to put in my rams, 3 briggs, and my clown plec. I'm loving corys just now and my lfs have emailed me to say the have the following at the following prices. (US$ is roughly double)


Albino Cory £3.25
Bronze Cory £2.99
Green Brochis £7.99
Julii Cory £5.99
Melanistus Cory £7.99
Metae Cory £6.99
Peppered Cory £3.99 (lge £4.99)
Pygmy Cory £1.99
Similis Cory £6.99
Sterbai Cory £5.99


Suggestions please? Whats a good number to have? I know they like to be kept in groups. Also I've seen alot of people saying the're changing their substrate to sand? Can they be kept with gravel? If not I'll change to sand!

Ooh also because the're are rams going into the tank it's at 26 degrees (celcius) Is that too warm?

Thanks guys!

[Lupin]

The bronchis will be too large for a 20g at 3-4 inches. I'd pick the pygmy cories. Prices are also reasonable.:) Get 6-8 of them.

They can be kept in fine gravel provided the substrate has no sharp edges.

[Rbishop]

Pygmy, sand or gravel. Though in a small 20 gal tank, 6-8, the pleco and the rams is a lot of bottom fish.