40gallon Set Up

[PRW1988]

Alright, so I've found some very usefull information at http/badmanstropicalfish.com/brackish/brackish.html, this will be my first brackish set-up, I've got a 40gallon tank, a rena XP1 canister filter rated for 45gallons or less, and I'll be getting a full submersible heater this saturday, along with some 40lbs of play sand, oh an of course lots of salt and a hydrometer. Now, I've got some ideas for what I want in the tank, maily gobies, I was thinking of 1 Dragon Goby, Some knight gobies, some bumblee bee gobies, some Mollys, and mabye something else (not sure waht else...)

I need to know, how many of each fish would I be able to put in the tank? The Dragon Goby I want to keep as a single... Also, any other suggestions for fish would be great.


The tank itself is 36" long, 18" deep and 15" high. Also, I'd like to add some live plants to it.

My finaly question for the time being, would live corals survive in a brackish set up?

 

[ac106]

the knights will probably eat the bumblebees so you may want to choose between the two

 

[PRW1988]

Really?? I've heard that the knights are more peacful than the bumblee bees... hmm...... Well, how many fish would I be able to keep in this tank in total, including 1 dragon goby and atleast 3 Knight gobies?

 

[nmonks]

Alright, so I've found some very usefull information at http/badmanstropicalfish.com/brackish/brackish.html...

It's not a bad intro, but there are some things I'd personally take issue with. Celebes rainbowfish definitely aren't brackish water fish, for example, and glassfish are only marginally brackish water fish and won't be happy at SG 1.010.

this will be my first brackish set-up,

Welcome to the club!

I've got a 40gallon tank, a rena XP1 canister filter rated for 45gallons or less, and I'll be getting a full submersible heater this saturday,

Do bear in mind manufacturers tend to over-rate their filters. So while that filter may say it works on 45 gallons, that is measured without filter media installed and with the filter at the same level as the tank, not underneath it. So your mileage will actually be significantly less. In other words, do water tests, and don't overfeed your fish.

along with some 40lbs of play sand, oh an of course lots of salt and a hydrometer.

You won't need 40 lbs of sand. 10 lbs will be plenty. All you need is to cover the bottom of the tank to a depth of about 1 cm. I'd also add some smashed up seashells, such as oyster and mussel shells. These will not only help to buffer the pH and hardness, but they also help to make it look more "under the sea" than plain sand. Gobies also like the hiding places!

Now, I've got some ideas for what I want in the tank, maily gobies, I was thinking of 1 Dragon Goby, Some knight gobies, some bumblee bee gobies, some Mollys, and mabye something else (not sure waht else...)

As ac106 mentioned, knight gobies are very predatory and will eat bumblebees, baby livebearers, and anything else they can catch. Dragon gobies are harmless, despite their size. They are awkward to feed though, being filter feeding fish and algae eaters. You'll need to provide them with suitably small food such as brine shrimp and bloodworms, plus algae tablets. They love live brine shrimp, and swim about like whales gulping them down!

I need to know, how many of each fish would I be able to put in the tank? The Dragon Goby I want to keep as a single... Also, any other suggestions for fish would be great.

There are now two books on brackish water fish, mine and the Aqualog one. Either of those will give you tonnes of ideas. Also read through some of the posts here, and check out my FAQ. Brackish water fish may be sold as freshwater or marine fish as well, so you need to learn to spot them in tropical fish shops.

The tank itself is 36" long, 18" deep and 15" high. Also, I'd like to add some live plants to it.

A trifle small for dragon gobies -- they get to 40-50 cm long -- so you'll need to be creative if you want the tank to look nice rather than just a big fish trapped in a small aquarium. I'd perhaps tend towards something else, maybe spaghetti eels if you can find them, or failing that peacock spiny eels, which are fine at SG 1.003-1.005, and perfectly safe with knight gobies and mollies. Alternatively, concentrate on the bumblebee gobies and then add perhaps figure-8 puffers and/or flatfish, and maybe even some nerite snails as algae eaters. Forget about plants. While do-able in brackish water, I personally find them annoying because they don't really work well with burrowing fish. The exception are Java ferns, which you buy stuck to wood or rock and can arrange easily.

My finaly question for the time being, would live corals survive in a brackish set up?

No, no corals in the trade are viable in brackish water tanks. Stick with snails, shrimps, and at SG 1.010+, marine blue-leg hermit crabs.

Cheers, Neale

 

[PRW1988]

WOW!!!! ~_~ Neale you rock Alright... Now I read that fire eels are fine in brackish water, is this true? I've got a 120gallon tank (upgrading to a 200+ tank in like 4 months) with my arowana, clown knife and (recently cured of hole in the head) oscar, would the fire eel be okay in the 40gallon until it grows large enough to be placed in the 120gallon? I ask because I was told by the LFS I'll purchase the eel from (on sale $11.88!) said that the arowana may eat the eel at it's current size and that eels are slow growers, apparently 2" every 3-4 months or something, not sure if that's a load of garbage, but just a thought...

Also, you mentioned crushed seashells, would Argonite work?

 

[nmonks]

WOW!!!! ~_~ Neale you rock

One tries...

Alright... Now I read that fire eels are fine in brackish water, is this true?

No, it isn't true. Fire eels need neutral, not too hard freshwater. There are some (low end) brackish water spiny eels, but none of them wants an SG above 1.005, and most don't even want that. So while you can keep (for example) a tyre-track eel in a very low salinity brackish water tank, there's really not that much point. Spaghetti eels (Moringua spp.) are far, far better if you can find them. They're in the trade, but uncommon, and probably a special order rather than something you'll bump into on your travels.

I've got a 120gallon tank (upgrading to a 200+ tank in like 4 months) with my arowana, clown knife and (recently cured of hole in the head) oscar, would the fire eel be okay in the 40gallon until it grows large enough to be placed in the 120gallon? I ask because I was told by the LFS I'll purchase the eel from (on sale $11.88!) said that the arowana may eat the eel at it's current size and that eels are slow growers, apparently 2" every 3-4 months or something, not sure if that's a load of garbage, but just a thought...

Spiny eels can be slow growers, but that's perhaps more because they're tricky to feed thank anything else. An adult fire eel would be fine with those fish, but you may need to grow on a juvenile a bit. They like earthworms best of all.

Also, you mentioned crushed seashells, would Argonite work?

Yep, that'll work fine. Put in the filter, and mix some in the substrate if you want (won't make a big difference in the substrate, but it'll help).

Cheers, Neale

 

[PRW1988]

Alright well thanks so much Neale, I think I know all I need to about Brackish set-ups to start my tank. My finaly question, in regardes to water changes... How often should I do them on a Brackish tank? Also, how should I change the water? Should I add the water to a bucket and put salt in until 1.005 or lower salinity is reached?

 

[nmonks]

Water changes should be done as often as with any other aquarium. At least 10% a week, and ideally something like 25% or more a week. On the one hand, salt reduces the toxicity of nitrate, but on the other hand some brackish water fishes, particularly puffers, are more sensitive to nitrate than most other fish. As ever, the lower the stocking in the tank, and the less high protein food you use, the lower nitrate levels will be in the tank.

Changing the water is similar to how it is done with marine tanks: Make up one bucket of brackish water, stirring in the salt and then letting it sit for 20 minutes. Stir again. Take out a bucket of water from the aquarium. Add the bucket of "fresh" brackish water. Repeat as required.

Never, ever, add salt directly to the aquarium.

If the tank is set up as a freshwater tank, just add the brackish water each week, and after a while it will gradually become brackish, in the process giving time for the bacteria to adapt. Easy peasy.

Cheers, Neale

Alright well thanks so much Neale, I think I know all I need to about Brackish set-ups to start my tank. My finaly question, in regardes to water changes... How often should I do them on a Brackish tank? Also, how should I change the water? Should I add the water to a bucket and put salt in until 1.005 or lower salinity is reached?

 

[PRW1988]

Alright, last question... I promise! regarding lighting, I'll be getting a 36" light hood, however would it be better to have a 30" lighthood for dimmer lighting?? Or do brackish fish prefer brighter areas?

 

[nmonks]

The fish don't care for the most part. There are a few species that like hiding places (e.g. moray eels and tigerfish) but most brackish water fish live in fairly open habitats. This is why they are big and active swimmers. Monos, scats, shark catfish, etc. will all swim about and actively avoid places that are too cluttered and shady (because that is where the predators lurk...).

If you're growing plants, then you want as much light as possible. If not, consider using things like grolux tubes that bring out nice colours in many fishes. Moonlight tubes are nice, too, especially with catfish.

Cheers, Neale

Alright, last question... I promise! regarding lighting, I'll be getting a 36" light hood, however would it be better to have a 30" lighthood for dimmer lighting?? Or do brackish fish prefer brighter areas?