i recently went to Hopkins Marine Station and they had these huge plastic round tanks. i was wondering if they sell those to the public. please give me links or something.

How big? I think www.aquaticeco.com sells hatchery type stuff.

Check your local aquaculture or farming supply centers...they have a variety of nontoxic plastic tanks available.
greg

do you think a 3100 gallon pool would work?

Well, what are you planning on keeping? We had discussed the use of small pools for cephs with OM, because of the low initial cost...I found one at Target for 79.00, and it included bulkheads and a filter with no metal parts...it is 12' in diameter, and 32" deep...you would have to live near the ocean though, or have one heck of an expense account! (for the salt)
greg

good thing i live near the ocean

your local farm store has a wide variety of tanks. I just bought a 650 gallon one for under $260.00