Fishless Cycling Help Please

[Prime Ordeal]

I can't be bothered reading back through the thread to see what you've been told so far but nitrates do not acidify the tank, they are merely an indicator of how much acid is being produced. If you were told that reducing nitrate removes acid they were talking nonsense.

What you should be doing is dosing no more than 1ppm ammonia and changing water when nitrite goes off the chart (preferably before), lots of aeration and a temperature of 30C, pH as close to 8-8.2 as you can get. You can safely miss an ammonia dose every second day and the ammonia eating bacteria will not suffer but it'll helpfully slow down the nitrite production meaning less water changes.

Also add a small pinch of fish food which will ensure macronutrients are available for the bacteria.

If you'd been doing that from day one I can guarantee that your cycle would have been less than three weeks.

 

[Flubberlump]

So if I started adding 1ppm of ammonia, would I increase it once it was being processed down to 0 ammonia and nitrite? The temp is 30C, and the pH is currently 7.5. The tap water pH is 8.

Nitrite is at 1.6 tonight.

 

[Prime Ordeal]

It's good that your water pH is 8 because that means as you do water changes to keep the nitrite down it'll boost the pH back up.

You don't ever need to go above 1ppm but if it makes you feel more confident you could raise it to two or three ppm at the end once it's processing the 1ppm ammonia and the nitrite in 12 hours.

I know this doesn't match with what the forum says but you'll have a much faster cycle by doing so and prevent any possibility of a mini-cycle after finishing cycling due to the wrong (high nutrient concentration) bacteria dying out and the right (low nutrient concentration) ones taking over.

I've done many cycles and supervised more and none have ever passed the three week mark to finish cycling when doing all the things I suggest.

 

[Flubberlump]

Ok thanks. Yes it is different, I just don't know as much about doing it that way that's all, so i apologise in advance for all the questions. So if the bacteria are capable of processing 1ppm of ammonia back to 0 nitrite, will I still be able to add my full fish stock at the end? I assume so as you say this limits the chance of a mini cycle.

I know that the forum way of doing it adds ammonia at a higher dosage to over compensate for the amount of waste that will be produced by the fish, but will 1ppm be sufficient to ensure this? I know that the fish will be constantly producing ammonia at a lower rate, rather than producing it all at once like we do during the cycle.

How often should I be doing the water changes? How much water should I change? Like I say, the nitrite is being processed at a constant rate, rather than building up to ridiculous levels like it was earlier in the cycle, but the bacteria don't seem to be multiplying as the nitrite never reaches 0.

I've added a pinch of fish food.

The stats this morning are: nitrite 1.6, pH 7.5.

Thanks.

 

[Prime Ordeal]

Ok thanks. Yes it is different, I just don't know as much about doing it that way that's all, so i apologise in advance for all the questions. So if the bacteria are capable of processing 1ppm of ammonia back to 0 nitrite, will I still be able to add my full fish stock at the end? I assume so as you say this limits the chance of a mini cycle.

I know that the forum way of doing it adds ammonia at a higher dosage to over compensate for the amount of waste that will be produced by the fish, but will 1ppm be sufficient to ensure this? I know that the fish will be constantly producing ammonia at a lower rate, rather than producing it all at once like we do during the cycle.

I can answer the above more easily if you tell me what fish and how many you intend to add immediately after finishing cycling.

How often should I be doing the water changes? How much water should I change? Like I say, the nitrite is being processed at a constant rate, rather than building up to ridiculous levels like it was earlier in the cycle, but the bacteria don't seem to be multiplying as the nitrite never reaches 0.

Then your cycle is almost done and you don't need to change any water. If you raise the pH a bit using bicarbonate of soda, raise the temperature to 30, and make sure that the tank water is as well aerated as possible the nitrite should drop pretty soon. Only dose ammonia every other day.

The tank aeration can be the deciding factor at this stage. For example, in one cycle I was supervising the nitrite was 'stuck' like yours and the person assured me that she was aerating the tank as much as possible (she had done all the other things I'd recommended). I asked her to use an air stone and within a few hours the nitrite had started to drop and quickly thereafter reached zero. The bacteria were just oxygen limited.

I've added a pinch of fish food.

The stats this morning are: nitrite 1.6, pH 7.5.

Thanks.

 

[Flubberlump]

Ok I'll try and get hold of an airstone. Before the stall, the nitrite was being processed to very nearly 0, it's only since the stall that it's been getting stuck, very frustrating!

I'm planning on 8ish Normans lamp eye killifish, a pair of apistogramma cacatuoides (or a trio, there seems to be some debate about what the sex ratio should be), 4 kuhli loaches, 4 corydoras, 4-6 each of rummy nose tetras and glass bloodfin tetras. I know some of those shoal numbers are a bit low, I already have some corys, kuhlis, and both types of tetra and am upping the numbers to a more acceptable level in the new tank. These are initial numbers, and I'll see about possibly getting a couple more of the shoalers if possible. I'll put the new fish in the new tank and monitor them, effectively using the new tank as quarantine, and then add my existing fish after a few weeks.

It'll also be heavily planted with pressurised co2. The plants will be going in before the fish.

The temp is 30C, I'll add a bit more bicarb tonight to raise the pH gradually.

Thanks Prime, really appreciate your input.

 

[Prime Ordeal]

So that's about 30 fish in all at once, right? I forgot to ask how big your tank is, did look (half heartedly!) but couldn't find it.

 

[Flubberlump]

It's 120litres. Yeah about 26ish small fish. Other than the apistos which will grow to be larger. Ideally, I'd prefer one shoal of tetras, but already have both species. Then one shoal at the top, one pair of apistos, and the cories and kuhlis at the bottom. I've got loads of caves and heavy planting too.

This morning, the nitrite was 0.8, and pH was 7.5. I added another 1/4 tsp of bicarb, which should bring it back up to around 8.

If it's not the nitrate that acidifies the water, what is it? Obviously there's something that caused it to drop from 8 to 6. My current tank has stable pH of 8.

 

[Prime Ordeal]

It's 120litres. Yeah about 26ish small fish. Other than the apistos which will grow to be larger. Ideally, I'd prefer one shoal of tetras, but already have both species. Then one shoal at the top, one pair of apistos, and the cories and kuhlis at the bottom. I've got loads of caves and heavy planting too.

This morning, the nitrite was 0.8, and pH was 7.5. I added another 1/4 tsp of bicarb, which should bring it back up to around 8.

If it's not the nitrate that acidifies the water, what is it? Obviously there's something that caused it to drop from 8 to 6. My current tank has stable pH of 8.

Yes, if you dose 1ppm then 26 all into a 120L tank at the same time will be fine.

The acidification comes from the ammonia oxidising bacteria. As they convert ammonia to nitrite they pump out hydrogen ions which bond to water molecules to form hydronium and it's this that acidifies the water column. The nitrite and nitrate are merely indicators of the level of acidification.

 

[Flubberlump]

Ok thanks that's great, I like to understand what's going on there scientifically, rather than just doing the same as everybody else without understanding why. Just ordered an airstone kit which should be here in a couple of days. In the meantime, the bacteria should continue to process the nitrite at the same rate so it shouldn't build up.

Will I need to keep the airstone in once the tank has cycled? Will it affect the co2 that I'll be running for the plants if so? I'd have thought it would?

Also, once I'm satisfied that the new fish are healthy and I move my existing fish into the new tank, will it go through a bit of a mini cycle? I'll be putting in 4 tetras, 2 corys, 2 kuhlis and 4 otos. I know I'll have to be very careful acclimatising the otos. So I won't be introducing a huge amount of waste suddenly with these few fish. Also, the plants should help with that shouldn't they? Correct me if I'm wrong though!

 

[Prime Ordeal]

Ok thanks that's great, I like to understand what's going on there scientifically, rather than just doing the same as everybody else without understanding why. Just ordered an airstone kit which should be here in a couple of days. In the meantime, the bacteria should continue to process the nitrite at the same rate so it shouldn't build up.

Will I need to keep the airstone in once the tank has cycled? Will it affect the co2 that I'll be running for the plants if so? I'd have thought it would?

You don't need the airstone once cycled, particularly if you're injecting CO2 as it'll drive the CO2 straight back out of the water.

Also, once I'm satisfied that the new fish are healthy and I move my existing fish into the new tank, will it go through a bit of a mini cycle? I'll be putting in 4 tetras, 2 corys, 2 kuhlis and 4 otos. I know I'll have to be very careful acclimatising the otos. So I won't be introducing a huge amount of waste suddenly with these few fish. Also, the plants should help with that shouldn't they? Correct me if I'm wrong though!

If you're not in a rush I'd do it in stages, tetras first, corys and khulis together next and, of course, the otos last, one group each day and you shouldn't see any mini-cycle.

You can put them in all at once but you would then expect a mini cycle which you could control with water changes and Prime until it levels off over a day or two. Not recommended though.

Either way monitor the ammonia and nitrite at least daily after adding fish.

 

[Flubberlump]

That's what I thought. The plants will be producing oxygen during the day anyway.

I thought adding the current fish in groups would be the way to go, especially if it'll only take 3 days to move them over! I certainly don't want a mini cycle! Thanks for confirming that. I've never lost an oto before, but I've read about people losing them when moving them into a new tank so I'll watch them very closely.

 

[Flubberlump]

Nitrite is 1.6 tonight, and the pH is still 7.5, so added another 1/4 tsp of bicarb.

 

[Flubberlump]

Stats this morning and tonight were the same: nitrite 1.6, pH 7.5.

 

[Prime Ordeal]

If you haven't got that airstone I'd get one as that could be your limit at the moment, and of course do everything you can to make the filter outlet disturb the surface water.