i have heard that if you have an already established tank, you could use that one to start the cycle on you other tank..... is this true???? i have 2 other tanks that are doing fine and i want to cycle this tank now beacuse if not i will have to wait a week to do so because i don't live near any pet stores and i will be in school all this week.... can you guys and gals give me a hand with this? and also, is there such thing as cycling a tank using fish (not a FISHLESS cycle) because then i could skip on buuying the amonia if i am thinking right.... hmmm maybe i'm crazy ! thanks alot

You can cycle with fish, but they will die / be really sick and it generally isn't recommended. That said, it is still often done with danios or other hardy fish. Since you already have two established tanks, however, put some gravel from one of those tanks in a nylon stocking and add that to your tank. You could also use filter media from one of the tanks, or just add the gravel from that tank without the nylon. This transfers bacteria from your established tanks into the new one and will really jump start the cycle. You could then add the ammonia as usual, but you will be able to add fish alot sooner than cycling a brand new tank without bacteria already in it.

This post has been edited by Vegan Peaches: Dec 5 2005, 12:40 AM

thanks alot !! this solves my situation nicley. that sounds along the same lines as I was thinking. oh and one other question how will i know when it is safe to add to my new tank? i think i may have lucked out on timing with my first tanks but this one being bigger and a up size for my larger fish, i really want to be sure about the saftey of my fish . thanks again.

Hi Scott MacAdam

The easiest way to get a new tank off to a great start is to clone it from an old one. I do it all the time.

Briefly, what's happening is this. A cycled tank has a colony of beneficial bacteria in it that is large enough to support the fish it houses. If you take part of it out, the bacteria will reproduce to replace what is gone. Since this beneficial bacteria is clinging to all the surfaces, especially the filter media and gravel, but also the glass, plants and decorations, unless you take a whole lot out, it won't be missed.

If you move some of the old filter media, which is probably the best thing to use, the remaining bacteria will repopulate the new filter media you replace it with. Then, add the old media to a filter in a newly set up tank. (Don't rinse it first; just add it directly.) The bacteria you have added will immediately be able to support a few fish and will gradually grow to be able to convert the waste products of more fish, provided you add them a few at a time.

If you have done it right, your tank will be cycled without actually going through the entire process from scratch. It works especially well if you are cloning a smaller tank from a large one. It's also a good idea to monitor the ammonia, nitrite and nitrate readings until you are sure it is well established.

sounds great! how long will the cycling take before it is safe to add fish though?

right away. say u take the filter media from a 30 gal and put it in the filter of a new 10 gal and can add a few small fish such as corries or guppies or something. 2-3 is a good start and every 5 days or so you can add 1-2 more till your fully stocked. just be sure to keep an eye on water parameters just incase.

Hi Scott MacAdam

I agree with fish_keeper2. Just be sure to add some fish right away so that they will produce waste products for the beneficial bacteria to eat. If you don't, the bacteria will die off.

Also, keep in mind that you can't add too much new fish at once, so that might mean moving small fish around from your other tanks until the bacteria colony is large enough to support one big fish. Then move them back to their original tanks. It's not a precise thing, you understand.

Oh and BTW, don't add any ammonia to the tank. The fish will produce enough on their own.

ok great! thanks alot guys ! i apprecate the help. this makes things easier !!!

Hi, I am having a Juwel Rio 300 tank this week and I am going to put one of the sponges from a Juwel Rekord 96 to start off the bacteria. From what has been said on this thread can I put fish in straight away? Or should I wait two weeks? Thanks.

how many and what fish do you plan to put in the new tank? it should be safe to add the most hardiest ones right away, need to to keep the bacteria alive and to grow, then in a week you can add some more. within less than a month you can have your tank fully stocked.

Thanks, I am moving my existing fish which are a 10" Common Pleco, 10 Dalmation Mollies and a Golden Apple Snail. They are all hardy. When the tank has settled I am going to get some Platies and then after a while some Guppies. I will see how it looks then. I am having a £30 pound fish voucher with the tank and they have put no time limit on it. I am very excited, which is very childish of me! I have also bought lots of new buckets as I have to move my old tank and put the new one in it's place. I will have to empty out a lot of water which I will need to put back in.

Morgan, are you keeping your 96 running aswell? from what you have said it sounds you aren't in which case when you have your 300 up and running up to temperature etc move over your blue foams from the 96 then add all your fish.

you your keeping your 96 running then add 1 of the blue foams from your 96 to the 300 and add say the common plec OR the mollies as soon as you shift the foam over, the apple snail can be shifted over when ever you like!

yeah i have my loach, betta and snail in there now ! things seem to be working fine. i can't wait to add in my other fish!