Cycling a 10g Using Established Filter Media

[SlickDiver]

Hi. I'm new here, but I'm not a newbie. I've been in the aquarium hobby for 20+ years. I usually do a fishless cycle from scratch because I'm usually not in a hurry. But this time I am in a bit of a hurry, so I'm trying to speed up the cycle of a new 10g tank using filter media from my established 75g tank. On the new 10g tank I'm running an AquaClear 20 and a sponge filter. That should be plenty of filtration. I filled the AquaClear 20 with filter media from my 75g. I also took some substrate (sand) from my 75g and covered the bottom of the new 10g. Then I dosed the new 10g to 1ppm of ammonia. By using the established filter media, I expected to see ammonia start to drop right away, but it's been several days and nothing has changed. How long does it normally take to initiate a cycle when using established filter media?

 

[10 Tanks]

Hi. I'm new here, but I'm not a newbie. I've been in the aquarium hobby for 20+ years. I usually do a fishless cycle from scratch because I'm usually not in a hurry. But this time I am in a bit of a hurry, so I'm trying to speed up the cycle of a new 10g tank using filter media from my established 75g tank. On the new 10g tank I'm running an AquaClear 20 and a sponge filter. That should be plenty of filtration. I filled the AquaClear 20 with filter media from my 75g. I also took some substrate (sand) from my 75g and covered the bottom of the new 10g. Then I dosed the new 10g to 1ppm of ammonia. By using the established filter media, I expected to see ammonia start to drop right away, but it's been several days and nothing has changed. How long does it normally take to initiate a cycle when using established filter media?

Hello Slick. The 10 gallon tank would be instantly cycled with the media and gravel from the established tank. There's no need to do anything else for the new tank. The new tank is ready for a few, small fish if this is your goal. Very small tanks require large, frequent water changes to maintain a steady, healthy water chemistry. Change half the tank water a couple of times a week and what little nitrogen is left will be diluted to a safe level in the new, treated tap water.

10 Tanks (Now 11)

 

[connorlindeman]

The tank is not ready for fish if there are ammonia readings.
When you filled the new 10g tank with water. did you dechlorinate the water prior to adding it? If not, that would have killed off all your bacteria.
I would encourage you to fill the 10g with fast-growing plants. This will speed up the process considerably.

 

[Essjay]

Is the donor tank planted?
I ask because I once used media from my main tank to set up a quarantine tank and added ammonia to see if it was ready to go. It wasn't, it took a full fishless cycle before it was ready for fish. I can only assume that the plants in the main tank removed most of the ammonia so there was only a minimal level of bacteria. And of course that minimal level would have been everywhere not just in the filter.

 

[SlickDiver]

The tank is not ready for fish if there are ammonia readings.
When you filled the new 10g tank with water. did you dechlorinate the water prior to adding it? If not, that would have killed off all your bacteria.
I would encourage you to fill the 10g with fast-growing plants. This will speed up the process considerably.

Yes, I always use water conditioner to dechlorinate the water before adding it to any tank. Like I said, I'm not exactly a newbie. Ammonia was reading 0 ppm when I added my fish.

 

[SlickDiver]

Is the donor tank planted?
I ask because I once used media from my main tank to set up a quarantine tank and added ammonia to see if it was ready to go. It wasn't, it took a full fishless cycle before it was ready for fish. I can only assume that the plants in the main tank removed most of the ammonia so there was only a minimal level of bacteria. And of course that minimal level would have been everywhere not just in the filter.

No, I took filter media from my 75g mbuna cichlid tank that doesn't have any plants.

 

[Essjay]

That's not the reason then

 

[SlickDiver]

Hello Slick. The 10 gallon tank would be instantly cycled with the media and gravel from the established tank. There's no need to do anything else for the new tank. The new tank is ready for a few, small fish if this is your goal. Very small tanks require large, frequent water changes to maintain a steady, healthy water chemistry. Change half the tank water a couple of times a week and what little nitrogen is left will be diluted to a safe level in the new, treated tap water.

10 Tanks (Now 11)

That's what I thought. Let me back up a little bit.... When I set up the new 10g, I used filter media from my established 75g. I thought that's all I needed to do, and the tank would be instantly cycled, like you said. But when I put a brood of fry in the new 10g, they became sick after a few hours. Half of them were at the surface gasping for air, and the other half were sitting on the substrate breathing hard. With both a power filter and a sponge filter, there is plenty of surface agitation, so I don't think oxygen depletion could be the problem. I tested the water and parameters were ideal (ammonia=0, nitrite=0, nitrate=0.5, pH=8.0, temp=80F). I removed the fry and put them into a breeder box inside my 75g. Some of them recovered, some didn't. But now I'm stuck trying to figure out the problem with the 10g. What made those fish get sick?

 

[10 Tanks]

Hello again. There isn't anything wrong with the tank that a large water change won't fix. Of course, the water needs to be treated to remove the chemicals the public water people put into the tap water to make it safe for you to drink. The water chemistry in a small tank can change in just a couple of days. This is why the water needs to be removed and replaced more often than a much larger tank.

10 Tanks (Now 11)

 

[SlickDiver]

Hello again. There isn't anything wrong with the tank that a large water change won't fix. Of course, the water needs to be treated to remove the chemicals the public water people put into the tap water to make it safe for you to drink. The water chemistry in a small tank can change in just a couple of days. This is why the water needs to be removed and replaced more often than a much larger tank.

10 Tanks (Now 11)

I get that. I'm familiar with water changes. I've been doing weekly water changes (the old-school way, with buckets) for 20+ years. But that's not what I'm asking. What I'm trying to figure out is what went wrong. Why did the new tank make my fish sick when the water parameters were nearly perfect?

 

[Essjay]

Was the 10 gallon and/or any decor besides the substrate brand new or old that had been in storage? Or perhaps a second hand tank/decor? I'm just grasping and straws and wondering if there could have been some contaminant got into the tank.

 

[SlickDiver]

Was the 10 gallon and/or any decor besides the substrate brand new or old that had been in storage? Or perhaps a second hand tank/decor? I'm just grasping and straws and wondering if there could have been some contaminant got into the tank.

The possibility of some unknown contaminant crossed my mind. But how would I ever know for sure? The tank, heater, sponge filter, and power filter were all brand new. I didn't have any decor. I rinsed all the new hardware (tank, heater, etc.) in tap water before I set it all up.

I've set up many tanks over the years, and this is the first time I had any problem like this. The only thing I did different from my usual process was to seed the new filter with media from an established filter. So, in my mind, I jumped to the conclusion that the problem must be something to do with the nitrogen cycle. But that doesn't make sense, because the water parameters were excellent even while my fish were dying.

 

[sharkweek178]

I have a theory. Sometimes fish are carrying some kind of pathogen (like a parasite) that they can normally handle and live with. Moving a fish to a new tank is incredibly stressful on the fish. When they are being netted, to them it must feel like a predator got them. That stress weakens the fish to the point where the pathogen that they previously were strong enough to handle now affects them.

 

[SlickDiver]

I have a theory. Sometimes fish are carrying some kind of pathogen (like a parasite) that they can normally handle and live with. Moving a fish to a new tank is incredibly stressful on the fish. When they are being netted, to them it must feel like a predator got them. That stress weakens the fish to the point where the pathogen that they previously were strong enough to handle now affects them.

Indeed! It's my understanding that stress is the underlying cause of most fish illnesses, including parasitic infections. Fish are constantly being attacked by parasites, harmful bacteria, etc. But most of the time, their natural immune system protects them. Excess stress will weaken their immune system, thus allowing infectious diseases to gain the upper hand.

That said, the fish in this case were fry. They were "born" in a breeder box, so I didn't even have to net them. I just gently lowered the breeder box into the 10g and let the fry swim out. For the first few hours in the new tank, they were behaving normally. If they were stressed from the relocation, they probably would have been acting strangely right from the start. Also, I eventually removed all the fry from the 10g and put them back into the breeder box, where some of them recovered. If relocation stress was the culprit, then this second relocation should have made them more sick, but instead it made them better.

 

[On_a_dishy]

What test kit are you using?