Setting Up A New Tank With A Matured Filter

[idlefingers]

Tomorrow I'm going to start setting up my 33 gallon tank. I have a spare, cycled filter on my 50 gallon ready and waiting to be moved across, so there shouldn't be any cycle in the new tank.

So, can I add fish straight away? Should I use some water from my 50 gallon tank in the new one or all fresh water? Should I buy some ammonia and keep seeding it for a week while testing the water to make sure it's not going to re-cycle?

Thanks for any help!

 

[mlawson]

I would add some of the water from the 50 gallon, maybe fill 30% of the 30 gallon it. As long as you monitor the tank carefully then I can see no problem in introducing fish straight away.

 

[idlefingers]

Okay, thanks!

 

[rdd1952]

Moving the water from the 50 gallon tank won't do any good. There is only a minimal amount for free floating bacteria in the water. Adding dirty water will do more harm than the few bacteria will help. When you can add fish depends on how many and what type you intend to add.

If it were me, I would set everything up, get the filter going, add ammonia and go ahead with a fishless cycle. It shouldn't take long since you are seeding the tank. Just because you are moving a filter doesn't mean the tank is cycled. The filter you move will definitely have some bacteria but not enough for the tank to be fully cycled.

 

[modaz]

Moving the water from the 50 gallon tank won't do any good. There is only a minimal amount for free floating bacteria in the water. Adding dirty water will do more harm than the few bacteria will help. When you can add fish depends on how many and what type you intend to add.

If it were me, I would set everything up, get the filter going, add ammonia and go ahead with a fishless cycle. It shouldn't take long since you are seeding the tank. Just because you are moving a filter doesn't mean the tank is cycled. The filter you move will definitely have some bacteria but not enough for the tank to be fully cycled.

dont add fish straight away, i made this mistake and lost loads, even when i used tank water and had put in a cycled filter

 

[Tolak]

It depends on the size of both filters, how long they have been running, what the stocking level is on the 55, and what the planned stocking level is on the new tank. What you plan on doing is cloning a tank, something I, along with others, have done many times.


Let's say for example you have a mature 50 gallon tank with 20 bronze corys, and two identical filters. You could take 10 corys, one filter, and put them in another 50 gallon. You shouldn't experience any cycling problems at all if you properly dechlorinate the water. I do this all the time dividing up angel spawns as they grow.

A mature colony of nitrifying bacteria will double in about 24 hours. This means you could do the same thing by taking half of your media, adding it to a new tank, and immediately adding new fish. I keep spare filters running all the time, remove them from the tank they are running on, and add them to new tanks. When I take the tank down I replace the filter in a running tank to keep it cycled. I do this if I get new fish in, or have a spawn that hatched out.

 

[Boids-n-more]

Something else to take into effect is once you split your filters up and start your new tank your takeing away from one to add to another. If your stalking numbers remain the same in your old tank it will go through a mini cycle until the bacteria has multiplied enough to handle the load. In the new tank where you put the seeded filter the bacteria will need food to survive , either fish waste or ammonia. You can stock the new tank right away but i wouldn't with a full load. Heres a lil formula i use when i seed a new tank , take the total waterflow per hour and get the percentage of flow from the seeded filter for example say you have 1000 gallons per hour and the seeded filter is 300 gallons per hour then thats 30%. I then find out what 30% of my fish is ( approx ) by size example 20 inches of fish would mean 6 inches of fish. I go bye size because a 6 inch fish will produce more waste than a 1 inch fish. I would then start with that much fish and over the next week or 2 add more fish every couple of days until i am at my stocking levels.

 

[rdd1952]

I like the formula. It makes sense and should work well. But as Tolak mentioned, even if you split your bacteria colony in half, it would be back to full strength in about 24 hours. So you really shouldn't see a mini cycle. By the time they create enough waste for it to start, the bacteria will be there to handle it. The exception to this is if you have very low pH water. Bacteria reproduction slows as pH levels drop. Optimal pH is 7.2 up to about 8.3. This article has some good information about bacteria growth and the effect of pH on it's speed.

 

[Tolak]

Since your nitrifying bacteria will double in around 24 hours you can take a portion of your mature bio media & start a new tank with little worry about any ammonia or nitrite spike. The mature media will catch up faster than ammonia will build up to any noticable or detectable level.

I run mostly sponge filters for bio filtration, and many tanks have 2 or 3 running when one will do. I have no problems with taking out a sponge filter, adding it to a tank I just filled with dechlored water of the proper temperature, and adding fish. I do this with everything from 3 week old angel fry to large breeding pairs. A week doesn't go by where I'm not setting up or taking down one or a few tanks. I don't lose fry at any rate that would be considered excessive for a breeding operation, and I don't loose breeders.

 

[idlefingers]

Thanks for the advice, guys.

I should have explained what the filter will be dealing with on the new tank.. the 50 gallon tank is quite heavily stocked and so the filter is currently dealing with quite a lot.

The new tank is not going to be heavily stocked at all; it's going to be a species tank with just two, young convict cichlids which I'm going to have a go at breeding (from what I read this shouldn't be very hard!). So to start with (because the convicts are still small), there shouldn't be any strain on the new filter.

 

[scorphonic]

This is a bit strange....alot of people say to put fish in straight away while some are saying not to. The idea of cycling a tank is to set up the filter with the correct bacteria right?? Well if he has a spare filter with the necessary bacteria already present in his current tank then isn't it common sense that he can put this filter into a new tank and put new fish in straight away??

Confused!

 

[Castellop123]

Cheers...

 

[scorphonic]

This is a bit strange....alot of people say to put fish in straight away while some are saying not to.

Everyone has different views and opinions... I, personally, think that if the filter is mature then you can add the fish straight away... Caution does, ofcourse, have to be taken...

Cheers...

How come you need to exercise caution if the filter is already prepared and has bacteria in there...what can hurt the fish?

 

[rdd1952]

How come you need to exercise caution if the filter is already prepared and has bacteria in there...what can hurt the fish?

Although the filter will contain bacteria, the tank will not be fully cycled. It will only contain enough bacteria to support a portion of the load of the tank it came from. For instance, if you were running 3 sponge filters, as Tolak said he usually does, in a 75 gallon tank and removed one of them to put into a new 75 gallon tank, the tank would only be approximately 1/3 cycled. And that's not taking into consideration whether the filter removed was the first, second or third in line in the established filter which could (no proof, just rationalizing) affect how much bacteria each filter had on it. The tank would also not have had a chance to build up any of the biofilm that is considered necessary for a tank to be considered mature so it would be more susceptible to problems.