What size tank is needed for a crocea


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I will be upgrading the lights on my 20 gallon, and want to know if I can keep a crocea under 6.5 watts of light. Also, can I put a crocea as the center peice in a 5.5 nano-reef?
errr...Are you sure you mean 6.5 watts?
If so then the answer is a definitive "No!"
O.K., then how much light is required? And does the tank depth matter ( the clam would be in a tank thats only 12" deep, and would be placed 6" from the surface)?
Were you saying you have 6.5 watts of light (basically a Christmas tree bulb)? Or were you saying you have 6.5 watts per gallon?
If per gallon...what kind is it?
I meant 6.5 watts per gallon ( I just re-read my post, and forgot to put per gallon, thanks for pointing out my mistake). I will be upgrading to a JBJ light. The specs are : 2-65 watt PCs (one 10,000 k, one actinic), 29.5" fixture length, and 3 cooling fans. I would just buy a 150 HQI pendant fixture, but it costs too much to be worth it (trust me, unless I have that light for at least a decade, PCs are slightly cheaper). Would this be enough light, and the right type?
Unless you are a clam expert, you'll need MH. You say you can't afford an MH setup. When I did my first lighting upgrade, I bought a 65w pc and a 55w pc for my 29. Totall of that was about $200. Well, I just bought a 400w MH setup, allmost new from a guy on the selling forum for $200. I wish I would have done that in the first place. You can find great deals on MH lights, just do a search on the selling/trading forum or e-bay.
SharonFay said:
I wouldn't even place a clam in the small of tank unless it was a Squamosa

Squamosas do not just get big, but they get big, fast.

A crocea is your best bet for a small tank as it is the slowest growing clam. BUT - it is probably the least tolerant of the clams IME with them as far as water quality goes. Sometimes a small tank fluctuates too much.
i had a crocea in a ~3 gallon tank for over a year. it was lit by 4 9w PCs. eventually moved it to another tank because this tank was too hard to scrape coralline off the sides. it was acrylic with a too-small access hole at the top.

6.5 wpg of PC might be a little short for a crocea in a 20.
maximas are more tolerant of water conditions than croceas, but in a small tank, any change (southward) of the water conditions is going to be hard on any clam.

IMHO, and IME, squamosa clams are very hardy and easy to care for. As project reef already mentioned, squamosas grow very rapidly, and get quite large. Derasa clams grow slightly slower, but can also attain massive sizes.

If you have your heart set on the bright colored clams--croceas and maximas, you have to buy the halide setup, IMO. I kept derasas and squamosas years ago under 4xvho's in a 40br, which is only 16" deep, and had great results.

Also, smaller clams need more nutritional supplementation---phytoplankton (IMHO) than larger clams. This may seem trivial, but I dose a lot of phyto, which might add excess nutrients to a small tank. Just something to think about.

If you don't already own a copy, the KNOP book on giant clams is excellent. I have an autographed copy (not bragging at all--I ordered it from a distributor, and it came signed---very cool.)