Originally Posted by papa_bear_21
I appreciate the quick response...
I'm looking at investing in a refractometer instead of a hydrometer, and am currently undecided on the filter for this tank. We are looking to have a few fish, some angels, maybe a puffer or 2 if capable of housing such beautiful fish. I have my eye on a porcupine puffer, but I think they may get a tad big...I think there may also be a goby or 2 in the tank, so maybe a gravel substrate would be good? There was a goby that my fiance and I liked, but we cant remember the name, it would scoop up gravel and move it else where then shake it out of its gills I think...dont remember...LOL
Thanks again for the advice,
29 gallons is too small for multiple angels. You could get 1 dwarf though but then you would be pretty limited as far as what other fish you can add due to it's size. A 29 gallon in this hobby is a very small tank and therefore you're really limited to very small fish. The majority of the puffer species are quite large, you could maybe skip the angel and get a valentini puffer, but again that's going to be the majority of your fish stock. You wouldn't be able to keep more than 1 valentini because they are aggressive toward their own species. You could maybe add two small fish with an angel or a valentini.
Gravel substrate really isn't the best option as it will trap a lot of detritus, old food, fish waste, etc which will cause problems with ammonia, nitrates, nitrites. Gravel might also carry toxins or impurities based on where you get it from. If you like the size/shape of gravel you could get crushed coral which is slightly better but you'll still run into the same problems as gravel.
Depending on what goby species you get, like the sand sifter types (the one you mentioned), they won't be able to sift through gravel. If you want that goby you'll have to go with a finer argonite sand which you could get from pretty much any LFS
. Also a 29 gallon is too small for more than 1 goby.
Sea horses are tough to keep unless you have a tank devoted to them. They can't have strong currents, lots of fish will pick on them, and they need a lot of corals, etc they can wrap their tail around. However, the specific corals they need have to be chosen carefully as some will deliver powerful stings to the seahorses. They are quite less hardy than most saltwater fish.