This is an excerpt from a message I wrote to member
anyways, slowly bring the specific gravity to about 1.015 over a series of water changes over weeks. Make sure the tank is cycled, they won't survive long in an uncycled tank. Unless of course you're up for water changes everyday =)
If you haven't got the space I can maybe take 2 of them off your hands, the rest you'll have to find homes for (vancouver aquarium?).
Setup up the aquarium with a crushed coral substrate, or better yet refugium mud which is what I'm going to use in my new setup. Have the tank (need to know your tank size) about half way full of water with alot of separate perches above water. Don't use anything that'll lower the ph, like driftwood. Use those cichlid rocks for any rockwork in the tank. They're also very territorial, so expect alot of bickering between individuals. You'll also probably notice that the largest male will take control of the entire tank. He's the head of the group, he'll control everything in the tank. when he wants a perch he'll take it from the other mudskippers. He's the reason I lost two mudskippers. so unless you have a rather large tank 12 mudskippers is going to be way too much for what you can keep in one tank. They also reach a size of 6" so you should work it out to 10 gallons per skipper. If you can get ahold of mangrove saplings you're one step closer to making the perfect mudskipper evironment. If you also have a rather large tank you could also keep fiddler crabs for a cleanup crew, they work great at keeping down the brown algae you're going to get (cyanobacteria comes with brackish water unless you have a protein skimmer). If you really want a good setup then big al's sells sumps and you could install one and run a protein skimmer through there. You'll also want to use a intake filter such as a fluval internal. you'll also want a submersible heater such as a rena cal or the tetra whisper heater (I recommend the rena cal). Keep the tank at a temp of 82 farenheit. If you use the coral substrate or refugium mud and the lace rock (big al's has it) that should keep your ph steady at 8.5.
When you change your water, you should have separate container to mix, and heat the spare water for 24hrs. Never raise the salinity more than .002 SG when you change your water, this can kill your beneficial bacteria
http://www.fishinthe.net/html/forum/viewtopic.php?t=4436
These fish HAVE to be kept in their own tank, no tankmates, they will eat them! Do not be tempted to buy the monos at big al's you need a much larger tank!
Even mollies won't last with mudskippers.
and for reference you have an african mudskipper, they come from the brackish mud flats in northern nigeria. they get to a max size of 6" and need a temp of 82F a ph of 8-8.5, feed them crickets frozen krill and brine shrimp are a treat once in awhile, try to spread the food throughout the tank on perches, they don't normally feed in the water.
Minimum tank size for 4 adult mudskippers - 90-100g with at least 40g of water.
Here is another excerpt from another message I wrote
Despite alot of claims, they really aren't beginner brackish fish and they need quite a large tank as you'd only be using about 30-40 percent of the tank's volume for water. Roughly 40 gallons of water minimum for 4 adult individuals (they grow pretty quickly), so a 90-100g would be your best bet. In anything less than adequate space they're very hard to care for as keeping water quality up is very difficult. These are large fish (at 6") that make alot of waste and are very messy eaters. They do best at a specific gravity of 1.015 with a setup consisting of coral substrate and calcium based rock as decoration. Another thing is that housing them in anything less than a group of 4-5 is a bad idea, like tetras you need to spread the aggression about as there is definately a heirarchy between the individuals. The only kind of mudskipper you're probably going to see is the nigerian mudskipper, it's the most common and some may say the "only" available mudskipper. Feeding them crickets, whole krill, blood worms (in a bowl) and on the occasion brine shrimp.