How long should it take for my 15 gallon tank to cycle?

Question

I have a cycled 5 gallon tank with a betta and a platy in it, and i just got a 15 gallon tank. Today I filled up my new tank and put a gallon of the water, and a cup of gravel from my cycled tank. So, approximately how long should it take for my 15 gallon tank to cycle?

I don't have a test kit.

thanks!

Answer 1

You can speed up the cycle process significantly if you move your filter from your 5 to your 15. Also see if you can move more gravel... the more the better.

With a 15 gallon, it should take about 3 weeks, but its difficult to say because your bio-load is so small.

If your worried about purchasing more fish, I would go ahead and get 2-3 more to speed up the process. ( A couple more platties would be perfect)

Answer 2

a month maybe

Answer 3

Unless you are adding a source of ammonia to the new tank it will never cycle.

As you dont have a test kit, the best option is to move EVERYTHING from the 5gal tank. Water, gravel, filter, fish, ornaments.. everything.

That way you will move the cycle bacteria from the small tank to the big one, all in one go. I suggest you then leave the tanks like that for 2 weeks before you get any more fish, just to let things stabilise.

After that time you can refill the 5gal tank, and move it's filter back in and use it as a quarantine tank for any new fish you want to get. It's filter will still have cycle bacteria, so you wont need to cycle it again from scratch.

Ian

Answer 4

1-2 hours? I wouldn't think so! Even if you have filtered media AND substrate from another tank, it can still take some time, depending on your water levels, and such. For example, some tap water has ammonia, which makes it harder to break into nitrates.

Since you're going from a 5 gallon to a 15 gallon, the substrate you may not have enough nitrate bacteria to cover the 15 gallons, and it could delay the cycle considerably. In the other side, sometimes adding a little bit of media from a cycled tank can make it cycle instantly.

Really, the only way for you to be completely sure if your tank is cycled is by buying a test kit and monitoring your water levels. If money is the issue, you can usually take a water sample to a pet store (Petsmart and Petco test water for free) and have it tested there, but it's always handy to have a test kit for these kind of situations, and to know when your nitrates are too high and require a water change, ecetera.

You really need to know the right time to cycle because either:

a) You'll be adding fish to your tank before it cycles, thus delaying it much more and hurting your fish's gills in the process

b) Waiting too long and letting the bacteria die, thus having to start the cycle all over again

Do you think you can perhaps add the filter from your five gallon, or some decorations that you might have in your five gallon?

Answer 5

for a tank that size usually tje nitrogen cycle ends aproximatley 1-2 hours because so try waiting that long and jsut to be sure if you want to be more on the safe side try waiting longer (all depends on your patience really ;) )