question on fishless cycling

[thartley]

I am running a fishless cycle on a QT and I am trying to make sense of what has happened so far. The tank is going to be used to make sure any new fish are healthy before they are introduced to the main tank.

I have a 10 gal tank with no substrate running a sponge filter with a powerhead (no air pump). I started the cycle using household ammonia on 8/15. On 8/16 I added a small cocktail shrimp to the water. I continued to add ammonia along with the shrimp because in the beginning, my ammonia readings were not very high with just the shrimp. I suspect it took a couple of days for the shrimp to start decomposing. During this time, I was able to get my ammonia readings up around 1 ppm, but that was with supplemental ammonia. I stopped supplementing around 8/19 or 8/20 and since about 8/21 my ammonia readings seem to have stabilized at around 0.50 ppm with just the rotting shrimp. On 8/22 I didn't have any nitrites, on 8/23 I had 0.25 ppm and on 8/24 I had somewhere between 0 and 0.25 ppm (it was less than 0.25 ppm). I checked for nitrates on 8/24 (12 hours after the nitrite test) and I have about 5.0 ppm.

There are a couple of things that I'm curious about. My ammonia levels are not dropping. I'm guessing this is because I still have a rotting shrimp in the tank. The other thing is that if I am nearing the end of the cycle, and I suspect I am since I do have some nitrates, it seems to have happened kind of fast. From what I have read, it should take from 2 to 4 weeks, and I'm not even at ten days yet. One of the reasons I went with the shrimp method was because I had read that some other bacteria will grow that help decompose other kinds of waste and these bacteria don't occur when the ammonia only method is used. Do I have to worry about 'residue' (junk suspended in the water) from the decomposition of the shrimp?

So, to summarize the questions:

Why aren't the ammonia levels dropping?

Am I correct in assuming that since I have nitrates, I'm near the end of the cycle?

Does the suspended debris from the rotting shrimp pose any problems to the future inhabitants of the tank?

Thanks.

 

[TankGirl]

You are going to have a sluggish cycle for a bit while we wait for the shrimp. You are showing nitrite, which is good, but with a lower level of ammonia in the tank it is going to take a bit longer. I would just sit tight and wait. The presence of nitrite is good, but you still have a ways to go.

In the end, once you are showing zero ammonia and zero nitrite and some trace nitrate, yet there is still a shrimp carcass in there, you will do a massive water change and try to get out as much debris as you can, and bring down the nitrate a bit. You will need to do this right before the addition of fish, since the bacteria you have patiently nurtured will continue to require ammonia.

I would put the tank out of your mind for the time being, and wait a week and check your levels again. Judicious neglect is in order here, LOL!

 

[thartley]

Thanks Tankgirl.

I thought I was supposed to be testing the various levels daily.

Would there be any point in starting back up with supplemental ammonia to get the levels higher?

I am hoping to quarantine 6 Zebra Danios and a few Ghost Shrimp when it is finished cycling and I'm concerned there may not be enough bacteria for the new load.

Thanks.

 

[TankGirl]

You could definitely supplement with ammonia to get your levels up, but not too high.

Sometimes when I get frustrated and impatient with a cycle I have to just make myself leave it alone for a week, still adding my ammonia but not testing, so I don't make myself crazy wondering, "okay, maybe TODAY is the day..." After I have kindof put the tank params out of my mind for a while I'll remember and test it, and lo and behold, progress! Like "a watched pot never boils" kind of situation.

 

[gamma]

thartley, I just finished my first fishless cycle on a 10g. My numbers were a bit different, but it worked, so I thought we might compare. I started by adding approx. 6.6ml clear ammonia, which brought my ammon. readings up to between 5 and 6 ppm. I added this amount every day, my nitrite readings rose gradually until on the sixth day they read 20+ - a big nitrite spike compared to yours (curiously, my nitrates rose quite a bit too). At this point I cut the ammonia to 3.3 ml per day, and this continued with high nitrite and nitrate readings. After 5 days I replaced about 2 gal. with "dirty" water from my goldfish tank. For the next 4 days the readings ran high, but the next day, nitrites read zero! I continued to add 2.5ml ammonia everyday until I was ready to add fish, before which I did a 50+% water change. Testing at this point read 0 ammon., 0 nitrites, and approx. 30 nitrate - high, but I think a few small water changes should control this over the next few days.

I don't know if you can, but I added sword plants, gravel from my gf tank, and a piece of filter material from my gf tank's not-too-recently-changed filter. Anything that can introduce bio-bugs seems to help.

I'm no pro, just thought I share what worked for me!

 

[TankGirl]

Well, gamma, your cycle sounds pretty textbook to me, and you are so right that seeding will speed things along remarkably well.

 

[thartley]

I forgot to mention that when I initially filled the tank, I used about 3 gal of water from an established tank and I sloshed the filter material from the established tank around in this water, so the quarantine tank was seeded a little to start. This was another reason for supplementing with ammonia in the beginning - to give the bacteria some food while waiting for the shrimp to start decomposing.

I am planning on keeping some Cabomba in the tank once the fish go in, but I didn't put it in to begin with because I didn't want the plant to utilize the ammonia, nitrites and nitrates and throw off my test readings, as well as keeping the bacteria from getting their food.

 

[gamma]

I kind of figure the sword plants I put in to be sacrificial, they look pretty bad now...in my case probably adding to the detritus more than utilizing any nutrients or such. I think you should work on getting a bigger nitrite spike by keeping up the ammonia supplementation, then, like TankGirl says wait patiently!

When I get home I'll look for the website information I had that showed a graph of the approx. ppm levels of ammon., nitrites,& nitrates throughout the cycle. It gave me a lot of relief to know I was somewhere close - I'll get back to you with that if you'd like!

 

[gamma]

The following site has a graph that I found useful to follow. My numbers didn't fit exactly, but the trends were there, with the exception of nitrate which shot up pretty fast and stayed there.

www.fishprofiles.net/faq/begin-cycling.asp