# cycling a 40 gallon tank



## DTetras2 (Jan 20, 2010)

Hey, i hav a 40 gallon tank and i dont know wat fish i should put in to cycle it. After its cycled, im gona put in lake malawi cichlids. Wat hardy fish should i use to cycle the tank?:fish:


----------



## aspects (Feb 1, 2009)

if you are set on doing a "fish in" cycle, danios are commonly suggested. 
however, i would highly suggest looking into a fishless cycle as a better alternative.


----------



## DTetras2 (Jan 20, 2010)

y is this?:fish:


----------



## hXcChic22 (Dec 26, 2009)

Most people think doing a cycle without fish is more humane, as a cycling tank can be tough on fishies, even the hardy ones. 
Personally, we have three Rosy Red Tetras that we use. Put them in new tanks for a day or so to make sure it's safe. But we usually use already cycled water from our other tanks so we have a headstart.


----------



## ron v (Feb 24, 2005)

It takes 3-4 weeks (or more) to cycle a tank either fishless or with fish. Do a google search for "nitrogen cycle"... There are possible additives that will help. Using gravel from an established aquarium will help. Water from an old tank doesn't do much.


----------



## emc7 (Jul 23, 2005)

Don't buy fish just to cycle it and then take them back, you just double you chance of disease. Malawi cichlids are plenty hardy, so if you cycle with fish, use a few of the cheapest of the fish you want to keep and use a product that "detoxifies ammonia and nitrites" such as Prime.

Your choices are fishless cycle and fish in cycle. 

You can try to speed up the cycle with a seed of filter media from an established tank or one of the many "bacteria in a bottle" products. Stability is one. They claim everything from "instant cycle" to 2-3 weeks. If you do 'fishless" with a product, you can tell whether or not the product works. 

IMO fishless is less stressful for you and the fish. You don't have to choose between worrying your fish will die and dropping everything to change water when you get a high reading. But it can be more work as you care for an empty tank and then do a large water change before adding fish.


----------



## DTetras2 (Jan 20, 2010)

thnks. now another question i hav is how many african cichlids i should put in my tank (its actually a 37 gallon, sry). i want to put in some mbuna cichlids and maybe 1-2 peacock cichlids? ths would be a lot of help. :fish:


----------



## emc7 (Jul 23, 2005)

What shape it the tank? 4' long is so much better than a 3' long bow-front. 

If its a short tank, I'd rather see you look at Tanginikan cichids like Brichardi. But if you must get mbuna get only 1 male and only 1 type and stick to small ones such as P. Saulosi. Avoid Metriaclima


----------



## bmlbytes (Aug 1, 2009)

For the impatient fish keeper:

Seachem Stability for freshwater tanks
Instant Ocean Bio-Spira for marine tanks.

I have used both and they work wonderfully. 

With Stability you buy a 8.5oz bottle and every day for 7 days you add a certain amount of it (listed on the bottle). Fish can go in the tank the first day and after 7 days you should no longer need the Stability.

With Bio-Spira, you buy a certain size bottle depending on the size tank you want to cycle. There is a small bottle (100mL) for tanks under 30 gallons, and a larger bottle (250mL) for tanks 30 to 75 gallons. You add the entire bottle and wait for the water to clear up. It only takes a couple of minutes. After that it is safe to add fish, and there is no need to worry about cycling the tank.

I have had wonderful success with both products. My tap water has a pH above 7 (which Stability works best with) and my marine tanks get reverse osmosis filtered water. I have heard that these products will not work with a very low pH though.


----------

