Fishlessly Cycling But Want To Add Fish Gradually

[sneezy]

Am upgrading from a 60l to a 240l. Am going to stuff my sponge from current fluval 3+ into the new fluval 305 and then complete a fishless cycle. I will then transfer my current contents (18 tetras) into the 240l.

I will prob then add 10 pentazona barbs into the tank (dependant on availability) but then want to add the rest of my stocking gradually 1 species at a time. This is mainly due to financial reasons but also we'd rather play it by ear rather than creating a stockking that looks good on paper but then not like it a few months down the line.

Would this be possible or will I cause a mini cycle every time I add new fish?

Also how much time do you think I'll be abe to cut off my cycle by using the mature media?


TIA

 

[Miss Wiggle]

hi sneezy, the benchmark for cycling is when the filter bacteria can process 5ppm of ammonia and nitrite in 12 hrs, this means that you have enough bacteria to support a full load of fish on the tank.

if you only plan to stock lightly at the start you can choose to cut the corner a little bit and only cycle with say 3ppm which would give you enough bacteria for half a load of fish. it's exactly the same process, the only risk is that it's impossible to accurately guess how many ppm your fish will produce so only going for a part load means you may end up with a mini cycle if your fish produce more ammonia than you'd accounted for. however if you're only adding 10 barbs to a 240l tank i think it's fairly safe!

so with some mature media and then only cycling to 3ppm you should have a nice quick cycle, it's impossible to predict times but i'd be surprised if it takes the full 6 weeks that we expect normally.

for adding more fish basically the longer you leave it between new additions and the less additions you do at any one time the less likely you are to have a mini cycle, so if you never increase the fish load by more than one third and leave it a good 2/4 weeks between additions then you should be fine. but it's not an exact science so you do run a small risk however you do it.

 

[Schmill]

This is where I get really confused.... - lol

I thought that the slowest multiplying bacteria in our filters were able to double their numbers in 24 hours if there was the food available.
Does this not then tally that, (not that I would recommend it), you could double your fish load every couple of days?
I understand that of course the multiplication of the bacteria isn't instant, as it is with the fish, so you might get a 1 day mini-cycle, but I don't see why it takes longer than that.

Certainly not contradicting MW in anyway here, just trying to get it clear in my own head too

 

[rabbut]

Bacteria doubling numbers in 24 hours is dependant on ideal conditions for the bacteria If you have fish in the tank and you aren't keeping Malawis, you won't have ideal condidtions, so bacteria growth will be slower

Why are you going to fishless cycle if it's a strait upgrade? Why not just move the existing tanks filter across with the fish directly after the tanks got upto temperature (often refured to as tank cloneing) and there you go. After 4-6 weeks, you can take the old filter off and you are going well

For adding fish, you want to avoid doubling your numbers each week if possible, but adding upto the ammount you already have should be safe after giving it a few weeks to ensure it's all settled down after your move should be safe I'd mebe add 10 a week the the existing stock, or less, or less regularly if you want to remain confortable at all times.

A tank will always mini-cycle when you add more fish. The real question is if you can detect the mini-cycle. If you can, you've over-done the additions. If not, you were successful

HTH
Rabbut

 

[Miss Wiggle]

well put rabbut, if you do it properly the mini cycle will be such small amounts of ammonia and for such a short time that you'd never pick it up on a test kit, but it is still there.

it's only a problem if it's a quantity that a test kit can pick up and goes on for a day or two or longer.

 

[waterdrop]

This is where I get really confused.... - lol

I thought that the slowest multiplying bacteria in our filters were able to double their numbers in 24 hours if there was the food available.
Does this not then tally that, (not that I would recommend it), you could double your fish load every couple of days?
I understand that of course the multiplication of the bacteria isn't instant, as it is with the fish, so you might get a 1 day mini-cycle, but I don't see why it takes longer than that.

Certainly not contradicting MW in anyway here, just trying to get it clear in my own head too

Yes, rabbut's given excellent comment that the conditions in fish-in are significantly less ideal for bacteria than the one's you can create in fishless, so you've had the best part of the answer there..

I'd just add, for your thinking, that building a mature biofilter (a collection of biofilms on your biomedia bathed in water that has fresh oxygen and ammonia) is a more complicated thing than just the idea of two populations of cells and their numbers respresents it as. If you get into reading the scientific articles and the bacteriology texts, you realize we're over-simplifying it and its really quite a bit more complicated (perhaps falling into the realm of "you don't really want to know this" )

The 2 species we want are actually interspersed in niches and competing with other species throughout their entire life cycle and together with these other species are constructing rather complicated biofilm "communities." Some of the more recent research shows that the biofilms actually have little channels where the fresh water can flow and given stability and lack of disruption, they will have somewhat consistent and elaborate construction. In our filters and our fishtank maintenance situations, we cause many disruptions to their structures and make the process even more complicated! Of course, our disruptions are probably not all that different from many that nature presents.

Anyway, just mean to remind that mere cells and numbers do not represent the "mature colonies" in a very complete way!

~~waterdrop~~

 

[rdd1952]

As mentioned, simply moving the current filter over would cycle the tank as there would be enough bacteria in it to handle the fish you have. Sure, there is a small amount of bacteria that would be left behind on the decor and tank walls but it would not be enough to matter. If you don't want to run both filters at once, you could also just add the sponges from the current filter into the new one. The 305 has plenty of room for media and should easily accomodate them.

When adding new fish, I would stick to an increase of 1/2 meaning if you have 18, add no more than 9. That way the bacteria chouls catch up rather quickly and prevent any mini-cycle.

 

[Miss Wiggle]

When adding new fish, I would stick to an increase of 1/2 meaning if you have 18, add no more than 9. That way the bacteria chouls catch up rather quickly and prevent any mini-cycle.

assuming the fish are a similar size and produce similar waste of course

the important thing is not the number of fish but the bio load produced (how much ammonia is produced). if you want to know more about working out the bio-load of your fish pop over to the scientific forum and have a look at the topic called 'when is a cycle finished' and I believe there's something in there.

 

[rdd1952]

I agree and should have been more clear on that. Most community fish though are relatively close as to the amount of waste produced. Adding the 10 barbs to would probably be cose to half what the tetras produce depending on the type tetras. In any case, at the worst, I don't think you would be doing more than doubling the load in which case the bacteria should be up to full force in a day or 2.

 

[sneezy]

Thanks for all the replies. Cloning the tank would be ideal but I assumed that the media in the fluval 3+ (3 sponges) would not be sufficient to keep a 240l tank under control???

I really want to avoid getting in a situation where I'm having to water change daily because my bacteria is unsufficient due to the fact I'm 7 months pregnant.

I also have a fluval U2 filter currently running in my tank. Although I'm selling this with the tank the buyer doesn't want it for at least a month so if I put both of these in the new roma 240 along with the 18 tetras this would clone the tank


Just to clarify - if i did this when could I add the barbs and how many? How long before I could add the next lot?

If it helps over the space of a few months I want to add

rummynose tetras (current stock)
black neon tetras (current stock)
pentazona barbs
honey gouramis
blue rams
corydoras

although this is a very loose stocking plan and likely to change.

 

[rdd1952]

Since you're upgrading and moving everything from one tank to the other. Simply moving the media would be fine. That filter is already supportiing the bio-load of your tetras so it would do the same in the new tank. You would just need to add new fish slowly which is the case either way you go short of a full fishless cycle in the new tank.

I wouldn't add any new fish for a week or so after moving everything, just to make sure you don't have any type ammonia or nitrite spike. After a week of no ammonia and nitrite, then add up to the same bio-load of fish (would be better to add about half). Wait for the ammonia and nitrite to zero back out again and then add more. Of course, unless you are very confident with your fish store, you really need to quarantine the new fish for 2 to 4 weeks to make sure you aren't introducing diseased or parasite infected fish into your tank.

 

[sneezy]

thank you for all the advice. I'm very excited now. Just need the tank to arrive