Recycling A Tank

[Fadi]

Hey guys, I have had my fish tank for nearly 2 years, and I have never cycled it before. I just restarted my tank, with a couple mollies and 2 gourami.

From what I have been hearing in this forum, it sounds very important to recycle the tank.

Should I recycle it???

What will happen if i dont

How will It help my tank???

How long will it take???

 

[nino]

Was there a period when there were no fish at all in your tank? If so, for how long? Cycling means getting enough bacteria in your filter media to breakdown all the ammonia fish produce. With no fish in your tank, the bacteria get no food and this will disrupt your cycle.
How big is the tank anyway?

 

[Fadi]

well, the tank is 60 gallons.

This is what happened...

For some reason all the fish in the tank died, so we started the tank over.
We changed the water several times in one day, so there was practically new water in there. Then we let the water sit with the filter on for about 2-3 weeks and we just recently added new fish. 2 black mollies died but the other fish seem to be fine.

Any Ideas?

 

[Inchworm]

Hi Fadi

I wouldn't assume that any of the beneficial bacteria survived that length of time without food, but some of them might have and will begin to reproduce from the wastes your gouramis are producing.

I wouldn't assume, either, that you understand what cycling a tank means because many people have kept fish without understanding what the various terms actually mean. Do you have test kits for ammonia, nitrites and nitrates? If so, it would help the members determine if you still have living bacteria or not, if you would do the tests and tell us the results in numbers.

If you don't completely understand what the beneficial bacteria do, please don't hesitate to say so and someone will be happy to explain the process to you.

 

[Fadi]

LoL. Actually, I have no clue and never tested my tank for anything before. Where would you guys get the kits from and what will the bacteria do for my tank?

 

[rdd1952]

Hi Fadi and welcome to the forum.

You can get test kits from most any fish store or online (not sure where you live). I use the Aquarium Pharmaceuticals (API) kits. It seems to be the most common one on this forum. Make sure you get a master kit so you can test for ammonia, nitrite, nitrate and pH. In the US the API kit sells for about $25 to $30. It isn't absolutely necessary but it also helps to have a KH test kit too.

As for the bacteria, they breakdown fish waste (ammonia). First bacteria will form that transforms ammonia (a toxin to fish, more toxic as the pH gets higher) into nitrite (another toxin to fish). Once there is nitrite, another type of bacteria will form that transforms the nitrite into nitrate (only toxic at high levels).

Optimally, you should never have ammonia or nitrite in the tank. The readings on those should always be zero. Nitrate isn't broken down by bacteria and can only be removed through water changes. As long as the nitrate level is below 60 to 80 (preferable below 40), it is ok for the fish but high nitrate levels may well lead to algae problems.

Since you already have fish, you will have to keep a check on the ammonia and nitrite levels and do water changes as needed to keep the levels down below .5 if at all possible. Sometimes this may take daily or even twwice a day water changes of 15 to 25 percent.

If you had your tank for 2 years, it most likely was cycled, you just didn't know it. The bacteria will develop as long as there is an ammonia source which fish are (they like to eat and poop). Some fish are hardier than others and can handle the higher levels of ammonia and nitrite in a cycling tank. I have never had mollies or gouramis so I'm not sure how they will do in a cycling tank. Just get a test kit and keep an eye on the ammonia and nitrite. Good luck.

 

[Inchworm]

Hi Fadi

This whole thing sounds a lot more complicated than it really is. Once you get used to using the kits, they will enable you, with only periodic checks, to head off any problems that might be starting in the tank too.