If i was to setup a lil tank for bumblebee gobies, how much salt would i need to add per litre?
Salt isn't 100% essential with BBGs, but it certainly helps. Aim for around 9-15 grammes per litre, or an SG of 1.005 to 1.010. That's fine for not only BBGs but a wide variety of other brackish water fish.
Could i use marine salt or would it have to be that aquarium salt stuff that comes in a green box.
Marine salt mix.
What size tank would they need?
BBGs need about a gallon per fish. But that assumes there are plenty of shells and other caves for them to hide in, as they're very territorial.
I've never had a brackish tank before so all help is appreciated
Brackish water fish are -- almost by definition -- very hardy, and with few exceptions keeping them is no more difficult than standard community tropicals.
Oh yeah, my LFS doesnt keep brackish tanks so if i got them to get me one in, and they put it in freshwater, would it be alright for awhile?
BBGs would be absolutely fine. As would most brackish fish. Adapting from freshwater up to SG 1.005 would take you 30 minutes using the "drip method" to acclimate them, and from freshwater to SG 1.010 maybe an hour, tops.
Id need a hydrometer right to work out how much salt or whatever is in the tank (1.0003 or something,please tell me what it is)?
A hydrometer is a thing that measures the density of water. Since measuring salinity directly is difficult, we measure the density instead. The more salty the water, the more dense it is. Freshwater has a density of 1 gramme per litre. Normal seawater a density of 1.025 grammes per litre. Brackish water somewhere in between. So long as you buy a hydrometer calibrate to 25 Celsius and use it according to the instructions, you can't really go far wrong. I personally prefer the floating kind that look like glass thermometers. Other people find the swing-arm kind easier to use. Yet other people eschew both of these in favour of refractometers. It doesn't really matter much which you use, so long as you use them properly and maintain them as required.
As AndyWG says, a little time reading around will help. Most aquarium books contain at least a short chapter on brackish water fish, and there are a couple of good books out there as well, one edited by me and the other published by Aqualog. Both should be available online or in your pet store, otherwise ask your library to get hold of a copy. Brackish fishkeeping combines elements of both the freshwater hobby and the marine hobby, but it has some quirks all its own!
Cheers, Neale
