the only term I can even think of for this would be microcycling? would it work?

  • #1
Do I understand the nitrogen cycle and tank cycling properly in that the only real problem is when you DO have amounts of ammonia, nitrite, and nitrate in the water which are unsafe for the fish? If so, logic tells me that five sub 1 inch fish in a treated but non cycled 90 gallon tank will not be in much or any danger simply because of the huge volume of water and surface area compared to the fish, and the filter should slowly build a tiny bit of colony with just these few fish, and if I just add a few more tiny fish every week or month or so the cycle should be so low level that it is safe and not painful for them?

I only have five fish right now in my fresh but treated, filtered, and set up 90 gal, three small cherry barb and two tiny (3/4 inch) pleco (they may be common or BN of the spotted type). I have already been yelled at for getting two common pleco for this tank, please don't repeat it here.... not the subject for this thread, please! The point is there are five UNDER 1 inch fish in this aquarium, and I plan on only adding 6 a month or so, hoping to build up a tiny microcycle of sorts... just a little at a time... could it work? logic (above) says it should easily work...

The filter is a fluval 405 (340GPH) with three trays of those ceramic whatsits, some activated carbon, and proper phys filter materials.

Does this microcycle idea make sense? or no?... Yes I know it's not established norm, please don't yell at me I misunderstood things I was being told here and researching at other places... I'm trying to see if this is known not to work or if it might work well.

for those interested in pics current as of this posting:

Sorry, fullsize only of the tank, needed to actually see the fish in detail.
  • #2
In theroey, it might work, the problems I see are as follows

1. Add ing 6 fish a month, will more than double the bioload, with such a small coloney, you are likely to end up pretty much with a normal fish in cycle.

2. As you are planing to do things are on a level test kits cannot register, so you will not know when the cycle completes.

3. As yor fish grow, so will the bioload, so at the same time you are adding fish the bioload will be increasing from them.

4. How long have the fish been in the tank? It may just take a week or so for the toxins to reach a level the test kit can read.
  • Thread Starter
  • #3
that's just the thing... each month still adding only 6 fish of the same size will keep reducing the actual addition to the bioload, and at the beginning right now the load is so small that it is diluted into this huge (comparatively) tank, and as you just said it is so low that even kits cannot register it... if the problem that fishless cycling is designed to get around is high amounts of toxins in the water this will avert it through an entirely different means... same end, different method. I really don't see how this is a problem if the only real reason to worry about cycling (not measuring, different subject) is to keep the toxins low, and if they are so low the kits won't even register them, isn't that the whole point of cycling in the first place, to keep the toxins low and therefore the fish comfy?

The first month there is 5 fish, if I add 6 fish there will be roughly double the load, still near zero for this huge tank comparatively, but next month there will already be 11, and adding 6 to that is a smaller proportion... then the next month that will be adding 6 to 17 already in... then 6 to 23... allowing the colonies of helpful bacteria to grow as they become needed, the only truly big changes are in the beginning when the comparative tank size and thus dilution factor would be quite high...

It seems like this would be the natural way things happen as fish populations slowly move into an area and the bacteria follow them... to me anyway.

if it takes a week to get enough toxins to even register on the test kits, isn't that kinda the point of cycling and water changes in the first place?

I mean, I really don't understand how this could possibly not work... I am trying to figure this out and truly don't see how it could be a problem in this particular situation... color me confused...
  • #4
I'll go out on a limb and say sounds good to me. That was my process with a 75 gallon. Establishing all the necessary bacterial colonies takes time, once they are there, they can adjust to those changes in bioload with ease.
  • #5
The point is not to keep the toxins low. Toxins are toxic. The point of a fishless cycle is to eliminate entirely the fish's exposere to them. If say within a week you start reading .25 ammonia, even this amount isn't good for the fish. Doing a water change will lower them, but doing so eliminates the food source for the bacteria to colenize, so it would take months for the bacterial coloney to make it to be able to hand even this small bioload. In a normal fish in cycle, the toxins reach these levels in 24hrs, so the water changes slow things down, but not nearly as much as if it where taking a week to get there.

As for adding fish, as I said, you will have no good way to make sure the tank is cycled ( which with fish normally takes more than a month). Adding them before there is enough bacteria to process the waste already there would be like starting off with 11 fish, which very well could bring toxic levels in a day or two.
  • #6
But why chance it? Why not just let the tank cycle, then add? Also, pleco tend to be especially sensitive to water conditions. I'd worry with such small ones.
  • #7
For starters I do not believe you truly comprehend the nitrogen cycle. Nitrates are the end result. Striving to attain no measurable ammonia, nitrite or nitrate is just another way have saying you have an uncycled tank.

Secondly, the bacteria colony grows just enough to process the waste created. With so little a bioload currently, you are putting off the colonization of bacteria. A few months down the road, suddenly your tank will have more waste than your plants can process and you will be finally starting to cycling. This scenario will lead to disease and death.

Lastly, you most certainly were not "yelled at" in your other thread. I'm sorry you feel victimized by members cautioning you about housing 2 Common Plecos in a 90G planted tank. They may only be 3/4 inch today, but not planning for their adult needs now often does will not end very well. Life has a way of changing the best of plans.

Good luck with your tank. I hope things work out for you.

Similar Aquarium Threads

  • Locked
  • Question

Top Bottom