Moving Filter From One Tank To Another To Cycle A New Tank?

HI everyone,

I am new to the hobby and had a question about the nitrogen cycle and possibly speeding up the process on my already planned 2nd tank.

I currently have a 29 gallon tank that I am running two filters in, a Top Fin 30 HOB as well as a fluval U3 underwater filter which will be the permanent "quieter" filter for the tank once I remove the Top Fin after the nitrogen cycle is completed.

I want to start a 2nd 20 gallon high so I will have one tank upstairs and downstairs in the near future. This 20 gallon high will house only two angelfish which are currently small and living quite happily in the 29 gallon, however I want these two to eventually have their own tank downstairs where I can view them more often and where they won't have any nippers going after their long fins. I currently have no idea if they are paired off or how long that could take but they do spend most of their time in the current tank together.

So here are my main questions, once my current tank completes its cycle in another 2-3 weeks, can I just move the Top Fin 30 filter onto the new 20 gallon tank since the fluval U3 will already be cycled with the current tank and maintain it quite well since its rated up to 40 gallons? and would this along with adding some water, say 5 gallons from the current tank (25% of the new tank volume) make the nitrogen cycle of the new 20 gallon high tank occur within 1-3 days?

Thanks a lot

ps, my current tank is stocked with 6 small fish as recommended by a local fish store in business over 30 yrs that all 6 would be fine not only together in the long term but also to cycle the 29 gallon tank. So far, with light feedings and small fish in the large volume of water, the cycling is going slowly so I am sure that is a good thing.

 

I know it is possible to use an established filter in order to skip the long period of cycling into a new tank, but from what you say you want to use a young - if I could call it like that- filter from a just cicled tank which could be premature in my opinion.

 

Welcome to fishlore!!

Just so I understand.....

the filter you plan to use to seed the new tank is on a tank that is also not completely cycled yet? And once that tank is cycled you plan to immediately remove one of the filters on that tank? I worry that would mess up the very newly cycled current tank.....

As for using water from a cycled tank, that is useless. The beneficial bacteria resides almost entirely in the filter.

Your plan makes sense, but you can never expect an instant cycle, or even a 1-3 day cycle. So you will still want to keep a very close eye on the ammonia and nitrite levels for a couple weeks after doing this process. On both tanks!

Now...I have to mention, and I am sorry for this because I know you aren't asking for stocking advice....but a 20 gallon high is not large enough for 2 angelfish. It is hardly large enough for one. They may be small right now, but two adult angels, if they are not stunted, are way too big for a 20 gallon. :-(

 

Putting water from one tank to another is basically the equivalent of taking water out of your toilet and putting it in your next door neighbours. It has practically zero benefit.

If your existing tank is well cycled, established, matured, you can take the filter out, put it in the new tank, and be instantly cycled.

I would say your first tank needs to have been cycled for three months to really work, but given that you're only looking to move two fish to it, it might be okay.

Anders247 CindiL Al913 and various others will be able to give you better info.

 

HI everyone,

I am new to the hobby and had a question about the nitrogen cycle and possibly speeding up the process on my already planned 2nd tank.

I currently have a 29 gallon tank that I am running two filters in, a Top Fin 30 HOB as well as a fluval U3 underwater filter which will be the permanent "quieter" filter for the tank once I remove the Top Fin after the nitrogen cycle is completed.

I want to start a 2nd 20 gallon high so I will have one tank upstairs and downstairs in the near future. This 20 gallon high will house only two angelfish which are currently small and living quite happily in the 29 gallon, however I want these two to eventually have their own tank downstairs where I can view them more often and where they won't have any nippers going after their long fins. I currently have no idea if they are paired off or how long that could take but they do spend most of their time in the current tank together.

So here are my main questions, once my current tank completes its cycle in another 2-3 weeks, can I just move the Top Fin 30 filter onto the new 20 gallon tank since the fluval U3 will already be cycled with the current tank and maintain it quite well since its rated up to 40 gallons? and would this along with adding some water, say 5 gallons from the current tank (25% of the new tank volume) make the nitrogen cycle of the new 20 gallon high tank occur within 1-3 days?

Thanks a lot

ps, my current tank is stocked with 6 small fish as recommended by a local fish store in business over 30 yrs that all 6 would be fine not only together in the long term but also to cycle the 29 gallon tank. So far, with light feedings and small fish in the large volume of water, the cycling is going slowly so I am sure that is a good thing.

sr...

You can instantly cycle a new tank, by removing some of the filter media from the cycled tank to the new one. You have to be careful when you add fish to the new tank. Add them slowly and test the water in the new tank daily for traces of ammonia and nitrite, to ensure the bacteria in the new tank is doing the job of removing these two forms of nitrogen. If you have a trace of either, perform a 25 percent water change. This returns the water to a safe level for the fish and leaves a little nitrogen for the growing bacteria colony.

Old

 

sr...

You can instantly cycle a new tank, by removing some of the filter media from the cycled tank to the new one.

Would you still suggest this if the tank the media is being taken from had JUST finished cycling? I would be concerned that a tank that just completed it's cycle would be too fragile to remove a bunch of it's media....what do you think?

 

wow, thanks for so many quick replies, so to rephrase the question or pose a new possibility<

what if I move the two angels and the HOB filter to the new tank simulatneosly, thus reducing the load on the fluval u3 which is too big for the 29 gallon already anyway and establishing that filter with the angels in the new tank right away? would that help at all?

also, I find it hard to believe that a 20 gallon tank is too small for two adult angels that will likely max out at 6in each. I have read that 1" per gallon is ideal that this would leave 8"+ extra for the combined 12" angels??? please advise on this. thanks so much from a rookie. I guess I could move the 29 gallon downstairs and keep the smaller guys in the 20 gallon but that would be a major pain at this point lol.

 

Would you still suggest this if the tank the media is being taken from had JUST finished cycling? I would be concerned that a tank that just completed it's cycle would be too fragile to remove a bunch of it's media....what do you think?

I agree with both. I wouldn't call it cycling the new tank, your just putting another tanks water through cycled HOB filter media, which can instantly "cycle your tank".

However, your BB will grow only to a size that is relative to the amount of Ammonia your fish produce. So, yes you could have a minI cycle in both tanks because there is not enough BB in either filter.

My suggestion is this, if you can, add the new fish (for the second tank) into your already established tank (tank #1) for 2 - 3 weeks. Let the BB build up enough to where it can handle the bio load. Then move 50% existing water from tank #1, the HOB filter, and the new fish to tank #2.

 

Inch per gallon rule is inaccurate. You have to factor in activity level, and bio-load and aggression levels when stocking a tank. The inch per gallon rule is typically best applied when you are trying to decide how many little schooling fish to put into a tank for example. When talking about larger fish, that rule does NOT apply. Would you put a 10 inch fish in a 10 gallon tank??????

Angelfish can be very aggressive fish as adults. And in a cramped space like that, they could likely end up not getting along as time goes on. I also doubt they will reach their full size potential in that tank. :-(

Edit: yes, the 29 would be much better than the 20. (but still not ideal for two angels, one would be better) So if you need to keep both angels, you really should give them the 29 gallon rather than the 20. I would also make them the only two middle swimmers in the tank. Their space will be very limited in a 29 and having a bunch of other fish will just make it worse.

 

Would you still suggest this if the tank the media is being taken from had JUST finished cycling? I would be concerned that a tank that just completed it's cycle would be too fragile to remove a bunch of it's media....what do you think?

biz...

As long as you've done several daily tests and have had no traces of either ammonia or nitrite, the tank is cycled. You can move a portion of the media from the cycled tank to a new one. Just replace what you removed from the cycled tank and test the water in the new tank every day for a while. You have to check to make sure the bacteria colony in the new tank is working.

It's important to understand that bacteria grows on all the surfaces in the cycled tank, not just in the filter media, so there's a considerable amount of bacteria living in the established tank. Also, bacteria reproduces very quickly. The bacteria you removed from the cycled tank will repopulate the new, replacement media in just a few hours. The key thing is to test the tank water in the new tank for a few days and change the water if needed.

Old

 

Then move 50% existing water from tank #1, the HOB filter, and the new fish to tank #2.

I highly suggest not using tank water.....That will accomplish nothing but just moving dirtiness over to the new tank. The beneficial bacteria does not live in the water column.

 

I highly suggest not using tank water.....That will accomplish nothing but just moving dirtiness over to the new tank. The beneficial bacteria does not live in the water column.

But wouldn't using 100% brand new water be too much of a parameter swing for the Angels? I only say use existing tank water so its just like doing a 50% WC on both tanks.

 

HI oldsalt777 I didn't need such a long winded response, but thanks. LOL

I am fully aware of everything you said. I just wasn't sure if you recognized that the OP was talking about taking an entire filter off a tank that just completed it's cycle. In my opinion, that freshly cycled tank is not established enough to be removing an entire filter as soon as it completes it's cycle.

My question for you was simply....does this info change your response at all?

 

But wouldn't using 100% brand new water be too much of a parameter swing for the Angels? I only say use existing tank water so its just like doing a 50% WC on both tanks.

I see your point. I guess I would think if the water is coming from the same water source, the parameters shouldn't change that drastically between the two new tanks.....They are both very new tanks using water from the same source....

 

I see your point. I guess I would think if the water is coming from the same water source, the parameters shouldn't change that drastically between the two new tanks.....They are both very new tanks using water from the same source....

Yup, that's his biggest issue, two very new tanks. He should wait a month or two before attempting to start a second tank with existing filter media. The first one is not even cycled yet.

 

thanks all, I am not going to poach the HOB filter until the current 29 gallon tank is fully cycled and I can wait a month or two past that but just don't see how much waiting that long will matter with just 6 small fish in the tank anyway and the two filters rated for upwards of 70 gallons combined. at this point, based on reading some other blogs about angelfish, I will put the two small angelfish in the 20 high together until they get bigger and see how they like. then I will possibly do a swap in a 8-12 months to move all the ones in the 29 to the 20 and the two angels back to the 29 lol.

 

also, what about an answer to this question,

"what if I move the two angels and the HOB filter to the new tank simulatneosly, thus reducing the load on the fluval u3 which is too big for the 29 gallon already anyway and establishing that filter with the angels in the new tank right away? would that help at all?"

 

thanks all, I am not going to poach the HOB filter until the current 29 gallon tank is fully cycled and I can wait a month or two past that but just don't see how much waiting that long will matter with just 6 small fish in the tank anyway and the two filters rated for upwards of 70 gallons combined. at this point, based on reading some other blogs about angelfish, I will put the two small angelfish in the 20 high together until they get bigger and see how they like. then I will possibly do a swap in a 8-12 months to move all the ones in the 29 to the 20 and the two angels back to the 29 lol.

I may have missed it but what are the "small fish"?

 

also, what about an answer to this question,

"what if I move the two angels and the HOB filter to the new tank simulatneosly, thus reducing the load on the fluval u3 which is too big for the 29 gallon already anyway and establishing that filter with the angels in the new tank right away? would that help at all?"

See my suggestion in post #8. I think that answers your question. But again, need to know what the small fish are.

 

Ok AquaFranklin I see what you mean in post 8. However, I already have all 6 fish in the 29g, so there will be no "new" fish going into the 20 gallon high downstairs. I will just be re-homing the 2 angels, and HOB filter and say 25% of current tank water to the new tank. Could I make this move all in the same day when the current tank is done cycling?

current stock are two rainbow fish (less than 1.5 each), two swordtails (one 2" and one 1.5").

Thanks

 

Once the tank is cycled steady for a couple of weeks (in this hobby don't rush things), then yes, move all simultaneously. I would do the water first, and fill up the the rest of the second tank (20g) with new water. Get it to the same temperature as the first tank (should take a couple of hours), then move both the HOB and the Angels at the same time. Test both tanks every day and perform WC's as needed.

This is only my suggestion, please take all of their other posts into consideration, there is a lot of useful information just in this thread alone.

 

awesome, thanks for the info everyone.

 

HI oldsalt777 I didn't need such a long winded response, but thanks. LOL

I am fully aware of everything you said. I just wasn't sure if you recognized that the OP was talking about taking an entire filter off a tank that just completed it's cycle. In my opinion, that freshly cycled tank is not established enough to be removing an entire filter as soon as it completes it's cycle.

My question for you was simply....does this info change your response at all?

biz...

The second filter is generally used in case one fails. This why I said remove a part of the filter media from one, I didn't recommend moving one filter.

The post may have been long winded. But, better to repeat or explain in better detail than to leave something out and make an error in tank management.

Old

 

Ok AquaFranklin I see what you mean in post 8. However, I already have all 6 fish in the 29g, so there will be no "new" fish going into the 20 gallon high downstairs. I will just be re-homing the 2 angels, and HOB filter and say 25% of current tank water to the new tank. Could I make this move all in the same day when the current tank is done cycling?

current stock are two rainbow fish (less than 1.5 each), two swordtails (one 2" and one 1.5").

Thanks

australian rainbow fish?? they grow big, I hope you know that.

 

It's important to understand that bacteria grows on all the surfaces in the cycled tank, not just in the filter media, so there's a considerable amount of bacteria living in the established tank. Also, bacteria reproduces very quickly. The bacteria you removed from the cycled tank will repopulate the new, replacement media in just a few hours. The key thing is to test the tank water in the new tank for a few days and change the water if needed.

Hey Old, just wanted to correct this about the nitrifyers repopulating in a few hours. Though I wish that were true it is not. Our autotrophic bacterial are very slow to multiply and only double once every 24 hours or so. The heterotrophs (organic decomposers) on the other hand, can double every 20 minutes.
I do agree they grow on all surfaces though and especially where there is a lot of O2 and space to grow like ceramic media.

 

just dwarf neon rainbows, max 3"