FishProfiles.com Message Forums

If I did 25% water changes every week starting the week after everything (including fish and live plants) was put in the tank, how long would it take the tank to cycle? I've read that its better to let the tank cycle on its own, and changing water only slows down the process of cycling. Well, I don't want to kill my fish. I'm even using nitromax and cycle like I should. I've also heard that If I keep doing the 25% water changes every week that my tank will never cycle. I have a hard time agreeing with that or seeing the logic. Does anyone agree?

Do the water changes. In fact check the ammonia and nitrites daily and if you feel it's higher than you want, do a water change. The tank will eventually get cycled without killing any fish in the process.

Most of the bacteria are in the filter and substrate not in the water. What you'll be pulling out with a water change is the food for the bacteria. But if your ammonia or nitrites are high there isn't enough bacteria yet to process what your fish are putting out so it's up to you to remove it until the bacteria catch up.

Good luck, Mike

It's alright to change SOME of the water while cycling. Keep an eye on your readings and change some if they get too high. Next time, do a fishless cycle. You won't have to worry about things like that. Good Luck!

Kim

I think next time I'll use bio spiro. I guess one good thing I have going for me is the amount of filteration. In my fluval I have bio max in the middle and top baskets, and I have bio max on the top of my power filter. I think my tank is completely cycled. The last water change I did was 1 week ago and there is no trace of ammonia, 2.0 ppm nitrate, and 0ppm. nitrite. I've had my tank running with fish for about 8 weeks now. The only other question that I have is in regards to my substrate. I just changed most of my gravel to sand (over a weeks period) and I now only have about 2 more pounds of gravel in there. Does this affect anything? I'm not too sure though.

By the way, what is a fishless cycle? Don't you need fish to produce nitrates? I can see putting ammonia into the tank, but how does the bacteria work to break it down? Maybe a dumb question, I don't know anyone who's done it before though.

Basicly what happens is, when you add ammonia, the bacteria colony grows and converts the ammonia to nitrites. Then another type of bacteria colony grows and converts nitrites into nitrates. Once you see the nitates in your tank, the cycle is complete.

[span class="edited"][Edited by T/A 2004-08-22 20:33][/span]