My fish cycle log...

andulrich4all

I'm not like a pro or anything at this, but I think others may agree and I have heard from my cousin who has had tanks all of his life and from my LFS that you should not do to many water changes in the beginning like that. Basically he said because if you keep pulling all of this stuff out, you are not letting the cycle happen the way it should. You need to let the parameters get a little worse and let the cycle do its natural thing. It can't do that if you keep replenishing it with new water.

jay2k6ie

Todays Results after 50% water change:

Ammonia 0 -0.15ppm
Nitrite 0 - 0.25ppm
Ph 7.6
Didnt test nitrate...

iamntbatman

It's possible that doing water changes during your cycle can slow the cycling process, but it's necessary for the health of your fish to keep those ammonia and nitrite levels low so I would keep doing what you're doing until the ammonia and nitrite disappear.

Tyyrlym

Changing the water during a cycle won't slow things down. The only way to slow a cycle with a water change is to do a 100% change. The 30 to 50% changes done to keep the levels low and fish healthy don't slow a cycle in the least.

Ammonia in the water that you detect is excess. In other words its uneaten ammonia. Think of it this way. You're sitting at a table eating. Does the amount of food sitting in front of you influence how fast you can eat it? No, it doesn't. Same with bacteria. They can only consume the ammonia so fast, they can only reproduce so fast. Higher concentrations of ammonia do nothing to change that. So long as there is excess ammonia in the tank the bacteria have plenty of food to eat and will consume it and multiply as fast as they can.

Why Water Changes During Cycling Are Good - Tropical Fish Forums

Like iamntbatman said, even if it slowed your cycle you have to do it for the fish's health.

iamntbatman

Hmm...I'd argue that the math in that post is over-simplified and cannot account for the growth rates of the bacterial colonies. For example, say you've got 1 ppm of ammonia in your water. Your bacteria at this same point in time are capable of consuming 0.25 ppm of ammonia per day. Using that guy's math, even after one day the bacteria colony will only have doubled in size, increasing their ammonia processing rate to 0.5 ppm/day. However...that's just an estimate. What if, for other factors we aren't accounting for, the population could explode to eight times its current size? Such a population explosion would be hamstrung by your ammonia ceiling. But you don't really see that, because your test kits only give you the snapshot, as that article says. I don't see any good reason why bacterial growth rates wouldn't be hindered by artificially low ammonia levels brought about by water changes during the cycling process. But, it's all really a moot point anyway. What difference does it make if your cycle takes a few days longer if it means saving your fish from ammonia exposure? And, if you're cycling fishless, why would you bother to do water changes at all during the cycle?

Oldman47

Actually all we can measure is the left over ammonia and nitrites, not all that is produced. As long as some is left over, the bacteria are not keeping up. It doesn't matter if the bacteria are losing ground at 1 ppm per day or .01 ppm per day. As long as they can't keep up, they will always have enough food to grow larger populations. When they can keep up we call that cycled which of course is not a problem. It takes no numbers to understand it this way.

Tyyrlym

The math doesn't perfectly simulate bacterial action but when you look at the experimental data where tanks were actually cycled there is a fairly good correlation between the math and what actually happened. It also jives with plain old common sense. A population explosion is what's happening in your fish tank. Bacteria only do two things, eat and make more bacteria. If they're eating enough they're making more bacteria. The rate of reproduction won't suddenly change because the organisms are too simple not to reproduce as fast as they can.

Growth rates won't be hindered by low ammonia concentrations because any ammonia you read in the water is food they haven't eaten, in other words you're measuring the excess that they can't eat.

jay2k6ie

Todays results:

PH 7.6
Nitrite: 0ppm
Ammonia: 0ppm
Nitrate: 5ppm

Im reading no nitrite or ammonia with a 5ppm nitrate after two weks of cycling with 6 pearl danios..
Is this a good sign?

Tyyrlym

I'd keep an eye on it for a day or two but the presence of nitrates after the ammonia and nitrite spikes would lead me to believe you're probably cycled. That's a very fast cycle but... well the water tests seem to point to it.

1077

I am with Ty on waiting at least five days,seven would be better and test every other day to be sure . The single biggest mistake that people make is adding too many fish too soon after the tank has established it's bacteria colony and by doing so The bacteria cannot keep up with the waste from the fish and the added food that is fed to these new fish. You would do well to add new fish slowly, one or two a week and feed them sparingly twice a day and no more than they can eat in one to two minutes. Perform weekly water changes and keep the filter rinsed out in old water you take out during these weekly changes. when the filter material gets too clogged and rinsing no longer is effective then replace it.