Considerations for max bioload during a fishless cycle

[khisanthax]

I've been following a few threads about cycling without fish and using pure ammonia. I'm wondering what the max bioload a tank can support under a fishless condition. I hear it said that your tank population should be rough 1 inch of fish per gallon of water. That being said if I'm using a fishless cycle and the ammonia is kept at 8ppm until the same dosage now has 0ppm of ammonia but then add even more ammonia so that the ppm rises to let's say 8ppm, you're not recycling the tank, you're just adding more of a bioload to handle more fish, essential, right?

Does this mean you can exceed the "1 inch of fish per gallon of water" rule since your bacteria culture can handle the load?

 

[TabMorte]

No.

You shouldn't over load your tank until it's fully settled (which is about 6 months old). There's still natural processes that happen after your tank is cycled that will be harder to manage if your tank is over loaded (most of us have a big bout of algae and the like).

Also if you just dump a ton of fish in your tank all at once you'll end up dealling with a lot of territory and aggression issues. It's best to add your fish slowly most passive to most aggressive with a few weeks between each new fish added.

 

[jediinthedark]

I mostly agree. You don't want to overload immediately, and you also need to learn the boundary's of your tank: each tank will have a different amount of fish that it can truly handle. The 1" p/gal is really just a guideline for people starting out. The true right amount of fish for a tank may be above or below that mark.

I'm not going to disagree with Tab's stocking order, but sometimes aggressive fish are forced into a more docile state when overcrowding occurs. This is how fish stores are able to keep so many aggressive and territorial fish in the tame 10 gal tank. But note that they don't do it for long.
Think of overstocking like an airplane. You can cram 200 people on a small plane and everyone will get along for a while, but if you force 200 people to actually live together stress will take some, aggression will take others, and the entire community will suffer as a result.

 

[TabMorte]

Oh I wasn't recommending over stocking.

Just I've found it's best to add your most aggressive fish last so that they're the 'new comer' in the tank and less likely to pick on more docile fish. The opposite way if the territorial fish is established and you add docile fish it will often regard them as 'invaders' and treat them accordingly.

 

[khisanthax]

I remember reading in the sticky about fishless cycling that once your done cycling you have to add the fish quickly or risk losing the colonies you've built up. However, that wasn't really my question. I was mulling over the concept of bioload as I understand it to mean the capacity that a cycled tank can handle with regard to biological waste and other materials that break down which may or may not be toxic to fish.

 

[TabMorte]

There is a maximum bioload to every given tank though that depends on a lot of factors beyond its size or how much ammonia you put in it (like is it planted). Also while cycling your tank takes 6 to 10 weeks to do, that's really only the most toxic period of a tank establishing itself which is why we stress that point - it isn't the end of the process at all. It really takes about 6 months for a tank to fully 'settle' as it where.

Yes if you do not put fish in the end of your cycle you will have no ammonia feeding the benificials and you will lose them. But that does not mean it's prudent to put as many fish as possible in there just because you 'can'.

Some one has in their tag line something like 'Only bad things happen quickly in a salt water aquarium'. I think that's a good way to look at most fish tanks. They're bonsi trees. They need to be pruned and shaped carefully over a long time to create the best result.

 

[cchase85]

This is a case where you probably aren't going to be happy until you get the answer you want to hear.

Just add the correct amounts and build up your stocking levels slowly once the cycle has completed.

 

[d3sc3n7]

Ok, while not trying to outweigh everyone else. I just have a few of my own points to add here.

As you get deeper into the fish keeping trade. You will start to pick up what most of us consider common knowledge. As far as stocking goes that is. It all depends on what your planning on putting in the tank.

Let me give an example of what I'm getting at, w/o making a VERY long post.

Ex: 1
Tank size: 55 gallons
Stock: Oscars
Now, Oscars get to say, around, 12in...maybe bigger. So, lets us stay at 12in. 12x5 = 56in. Using the 1in per gallon rule, this would only overstock you by 1gallon of water, not a problem, right? Wrong! Temperment aside, there is no way 5 fish, that are 12in each, will thrive in a tank that size.

Ex: 2
Tank size: 55 Gallon
Stock: Neon Tetras

Now, neons are only about 1in, full grown. So the 1in/gal rule says you can get 55 in the tank, right? Well, yes...but I personally would say you could put a few more, say 60 maybe. This is because they are very small, and each fish adds very little to the bio load.

Also, with a more established tank. (as tab stated) and more skill in tank maintenance you can push the stocking boundaries a little further.

So, over all..I would say, if this is your first tank. Don't over stock. Stick with the 1in/gal rule. Once you have been at it for a while, have a good solid routine down for taking care of the tank...then think about pushing it a bit.

 

[khisanthax]

My personal theme that I'm going for in my 55g is small fish. I'm trying to keep it under one inch for each fish. But I was really just wondering about the this concept of bioload and what else happens after the tank is done cycling. There's so much focus on finishing the cycle, but I don't remmeber reading anything about a second cycle or what goes on after in terms of processes.

 

[d3sc3n7]

Well, pretty much...your first 4-6 weeks are your beginning cycle. This gives you a good foot in the door, on your way to a well established tank. As your tank grows, your stock grows, your bacteria grows.

That being said...even though the bac. will catch up to the bio load. That does not mean its a good idea to push it.

Sorry, my answer isnt coming out that well in words.

 

[Lotus]

When you're talking about bioload, the only thing you're considering is the ability of the bacteria to process ammonia and nitrites. Sure, fishless cycling will get the bacteria population up, but it's not the only thing to consider.

A bioload that is too large will cause nitrates to rise fast, which is unhealthy over the long term. The oxygen availability is another factor in how many fish you can put in a tank. In addition, other factors like space for the fish can be an issue if the fish don't have enough room to get away from one another.

The main problem with overstocking comes when something upsets the normal running of the tank. If you have a filter failure or the electricity goes out, the higher the bioload, the faster the fish will die, due to oxygen shortage. If you are doing large weekly water changes to make up for an overstocked tank, and something happens like you want to take a vacation, or there's an emergency that means you're not there to do a water change, problems can happen very fast.

 

[d3sc3n7]

Exactley, thats pretty much what I was trying to spit out...it just didnt work out!

 

[kay-bee19]

I'm wondering what the max bioload a tank can support under a fishless condition

That would depend on the total surface area within the aquarium, substrate, rocks, decorations, and, most importantly, filter media (specifically biological filtration media) available for the beneficial bacteria to colonize.

...if I'm using a fishless cycle and the ammonia is kept at 8ppm until the same dosage now has 0ppm of ammonia but then add even more ammonia so that the ppm rises to let's say 8ppm, you're not recycling the tank, you're just adding more of a bioload to handle more fish, essential, right?

If your aquarium is able to process 8ppm of ammonia (and subsequent nitrite) within a 24hr period or less, I would say it is ready to support fish (which is different from having it start at 8ppm, and then eventually attain 0ppm after several days). Adding a particular quantity of ammonia in one single dose to bring ammonia BACK to 8ppm is something that won't typically happen in a aquarium containing fish. But if the aquarium is still able to process that accumulation of ammonia within a 24hr period (again), it may be considered fully cycled.

When preparing to stock a lot of fish all at once, I find that building up the beneficial bacteria colony helps immensely. If my 125gal fishless cycling tank can process 12ppm ammonia every day consistently for a week or more, has no nitrite, and has accumulating nitrates, it's ready for fish (as in a dozen or more 3"-4" inch fish added all at once).

I've tried it and done it on many occasions. My goals were to create more ammonia production than the eventual fish would produce (i.e., a tank that can process 12ppm of ammonia/nitrite daily can support a lot of fish added all at once; even the fish in my most heavily stocked tanks don't produce that much ammonia).

A bioload that is too large will cause nitrates to rise fast, which is unhealthy over the long term.

That's where water changes come in. Nitrate production is an expected consequence.

For example, if one desires to add a half dozen 11-inch fish in a 180gal tank (say, some good sized african cichlids like full grown nimbochromis venustus). Based on the behavior and requirement of that species, that tank is considered adequate and ideal for them, and isn't even ovestocked.

In an established tank they'd probably produce 50ppm of nitrate a week (or maybe less). If the ratio of ammonia:nitrite:nitrate are the same then at roughly means they're producing 7ppm ammonia daily. If during the fishless cycling process the tank is conditioned to process 12ppm of ammonia/nitrite within a day, that tank for all intents an purposes would be ready to support a half dozen 11-inch n. venustus added all at once. If it takes days for 12ppm to be processed, the tank wouldn't be ready for that amount of fish introduction.

Keep in mind that building the bacteria colony to the point where it can process this amount of ammonia and nitrite will take weeks (8-12+).

 

[khisanthax]

Great reply, I need to chew over that a few times. I like to understand things even if it's just a theoretical application.

 

[khisanthax]

descent: nothing to apologize for, I'm just pushing to understand =)