Doing A Fishless Cycle, 21 Days Running, Advice Please.

[rich05uk]

Hi all,

I'm doing a fishless cycle and wanted some advice as its been running for 21 days now and I havent noticed any reduction in Nitrites?

Its a 46 Gallon tank and on day 1 I added ammonia to get 5ppm, by day 2 it had already dropped to 2.4ppm, I added half the amount of ammonia again to get it back to 5ppm. By day 4 my tank could convert 5ppm to 0ppm within 12 hours, great.

Daily I have been adding 2.4ppm of Ammonia, each time this is reduced to 0ppm by the next morning.

Day 19, I added plants, rock & bogwood. I assume this is ok?

Day 21, so far nothing else seems to be hapening and I expected to see something happening to the nitrites by the end of 3 weeks. I had only been testing Ammonia, Nitrite, Nitrate & PH but today decided to do some additional tests to include Carbonate Hardness (KH), General Hardness (gH), Calcium Concentration (Ca2+) & Calcium Hardness (CaCO3). My results are as follows

Ammonia (NH3/4) 2.4 ppm (I had just added ammonia 1 hour before)
Nitrite (NO2) 3.3+ ppm
Nitrate (NO3) 110+ ppm (Not accurate due to high Nitrite Levels)
Potential Hydrogen (PH) 7.5
Carbonate Hardness (KH) 70 ppm (3.92 dH°)
General Hardness (gH) 340 ppm (19.04dH°)
Phosphate (PO4) 0.5
Calcium Concentration (Ca2+) 120 ppm
Calcium Hardness (CaCO3) 300 ppm

Everything seems fine to me, but for some reason my KH has gone down and is lower than i'd like, my tap water is usually 100ppm (3.92dH°). Also my gH has gone up and is higher than i'd like, my tap water is usually 180ppm (10.08dH°). What could have caused this and how do I prevent it in the future. I assume a 50% water change will bring them back into the desired range so I will plan to do a waterchange tomorrow. Ideas?

Any other comments about my fishless cycle and anything I might be doing wrong?

Thanks.

 

[redevilman]

My tank while cycling wasnt to disimilar to yours and miss wiggle advised me to do a 80% water change then top up the ammonia to 5ppm my nitrates shot back up to 5ppm then in about 5 days i was cycled

 

[Corleone]

Your kH will go down over time. The cycle produces some other byproducts that aren't tested for which affect water chemistry. The only thing I checked doing my fishless cycle was kH. It'll be reduced over time, and if it hits zero, your pH could crash (kH is the capacity of the water to resist pH change), which is bad. If it drops too low, a water change will help.

I never tested gH or anything else during my water test, but if your calcium hardness is rising, take the rocks you added out and test them all with vinegar. Some rocks will release calcium into your water. If that's the case, they'll fizz when vinegar is applied, and generally aren't suitable for a freshwater tank.

 

[rdd1952]

I would suggest a large water change to lower the nitrite and nitrate. It's posible that the tank can handle a normal amount of nitrite but if you have been adding 5 ppm of ammonia every day for 21 days, your nitrite could well be in the 50+ ppm range. A large water change (90%) will get the nitrite back to near zero so you can see what is happening. The fact that you have nitrate means that nitrite is being processed (unless the nitrate is in the tap water.

As far as the GH & KH are concerned, I wouldn't be too concerned during cycling. As mentioned, the oher by products can cause strange things to happen and it's quite normal for the pH to drop. Once you are cycled and the fish are in the tank, I don't think you will have a problem. In most cases, fish can readily adapt to the pH, GH & KH of your water as long as it's stable.

 

[waterdrop]

I agree with RDD. One or more large water changes are in order to clear out the nitrites and nitrates. If you have time to shut the filter down and do a 90% as RDD says, all the better, but sometimes what I do is just leave the filter on (this assumes the filter intake pipe goes quite low in the tank) and take the level down to just before it would break the filter siphon, then I fill the tank with conditioned water and let it run for a while, then I repeat the exact same process again. Doing it twice like this is sort of an easier process, but gets lots of the old nitrates out. You have to remember to condition and recharge with ammonia for the second fill.

At 21 days you sound like you are having a very normal experience, especially for those of us with a KH of 70ppm or below (in the "extremely soft" range) and it may take a long time fot the nitrite oxidizing bacteria to develop enough to pass the test of processing 4-5ppm within 12 hours.

~~waterdrop~~

 

[rich05uk]

Ok, its now day 26 so time for an update.....

I did a 60% water change on day 22, then another 40% water change on day 24, I have been testing daily the 4 main things Ammonia (NH3/4), Nitrite (NO2), Nitrate (NO3) and Potential Hydrogen (PH) and on day 25 there was still not much change in the results

I have been adding 4ppm of Ammonia daily and thankfully by surprise today after testing I had the following results

Ammonia (NH3/4) 3.7 ppm (I had just added ammonia 1 hour before)
Nitrite (NO2) 0.8 ppm
Nitrate (NO3) 110+ ppm
Potential Hydrogen (PH) 7.5

So it looks like its finally getting there as this is the first time the nitrites have come down back into the readable range of my test kit..

So I am now planning on testing again tomorrow (12 hours frm now) and if Ammonia and Nitite are both 0, can I assume once I have done a large waer change to reduce the Nitrates I can add my fish? If so, how much Ammonia do you think I should add daily to keep things going unil I get my fish?

Thanks.

 

[OldMan47]

I would make sure that you keep at least 2 ppm while you are checking the stability of your cycle. 5 ppm might be a bit better but as long as you keep feeding the bacteria a reasonable amount they will survive. Keep an eye on your chemistry for a few days before you actually stock with fish. Some people will get very hopeful looking numbers and have a minicycle a few days later so watch it for those days. After all your hard work, it would be a shame to subject the fish to a minicycle.