Coming from a long time freshie who recently converted to SW
, I have only one regret...not upsizing my aquarium while in transition. For me to sell my 90g used, and upgrade to a 150g would cost only $300 in the local classifieds. I had to buy everything new again when converting, except my heater. Converting is very close to starting from scratch... so if you have the opportunity (and space), consider upsizing during the transition, you may be happier in the long run.
If you'd like to keep with the similar sized aquarium, it may be cheaper to sell what you have and buy a biocube/nanocube which is already set up for FW
, instead of buying everything new again.
Oh, and there is no actual formula for figuring out how many size you can put in a SW
setup.. (not as simple as 1" of fish per gallon). You have to factor in half your space will be Live rock and a deep sand bed, so your 37g is more like a 20g. Plus SW
fish require more swimming room, and there is a larger bioload with SW
. The best way to find out how many / which fish you can house is to do what you just did... ask the experts, and they'll guide you in the right direction.