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Cycling a new tank with the old one still running, anyway to speed it up?

Muso1981

Member
Joined
29 Aug 2020
Messages
91
Location
Nottingham
Hi all,

I have a planted 120 litre tank with fish and shrimp, and I'm going to move all this over to a 200 litre tank. I was wondering if there way anyway of having a quicker/easier cycle by somehow using the old tank? I can't find anything on this anywhere but I thought if I put the new filter unit from the new tank into the old tank and run it along side the old unit would it collect the bacteria so that I could then transfer it into the new tank along with some fish, or wouldn't this work?

Thanks,
 
Hi all,
but I thought if I put the new filter unit from the new tank into the old tank and run it along side the old unit would it collect the bacteria so that I could then transfer it into the new tank along with some fish, or wouldn't this work?
Yes, it works. My suggestion would be to:
  • Take the media out of both filters.
  • Swirl the old filter media into a bucket.
  • Swirl the new filter media in the mulmy water.
  • Put the media back into the filters, putting both new and old media in both filters.
  • Connect the filters back up to the tank.
Is the new tank directly replacing the old tank? or could you run them simultaneously?

cheers Darrel
 
What substrate are you using in the new 200 litre tank? If you are using an aqua soil, be aware that most are loaded with ammonia which they then proceed to leach into the water column, so don't add any livestock for a couple of weeks. If you are using an inert substrate (and plenty of plants), you should be safe to add some earlier on.
 
@dw1305 The filters are totally different so the media can't be swapped around. The new tank will be replacing the old tank but this will be a gradual process, thanks for the suggestion so I could do this when I do my water change this weekend.

@Wookii I have Tropica soil powder in the new take, I wasn't aware of this so thanks. I've had water in the tank now for a week, I will do a water test to check before I put anything in. It sounds like I could have done the cycle with just the tropica soil then? I've got some tetra safe start which I'm going to add when I add the first few hardy fish.

Great advice guys, many thanks!
 
@Wookii I have Tropica soil powder in the new take, I wasn't aware of this so thanks. I've had water in the tank now for a week, I will do a water test to check before I put anything in. It sounds like I could have done the cycle with just the tropica soil then? I've got some tetra safe start which I'm going to add when I add the first few hardy fish.

On behalf of your fish, please don't do that. There is no such thing as a 'hardy' fish when it comes to ammonia tolerance. Fish are no more 'hardy' to ammonia exposure, than we are to asbestos exposure!

Tropica Powder (which I use) leaches a lot of ammonia for well over a week or more .You need to get rid of it with large (80%+) daily water changes for at least two weeks. Please don't consider adding any livestock until you have zero ammonia levels. You can ensure that either a) by using an ammonia test kit and producing repeatable zero ammonia results, or b) by simply waiting a month or more for the plants to start growing in well.

I know test kits aren't well thought of on this forum, but I consider an ammonia and nitrite test kit mandatory when starting a new tank if the 'simply waiting' technique (which is preferred) cannot be followed. The visual accuracy of either test can also be improved by using tap water as a base line zero-level comparison at the same time.
 
Hi all,
The filters are totally different so the media can't be swapped around
Fair enough, it isn't essential.

I don't tend to use the media sets that come with filters. I don't like floss or fine sponge in the tanks (I like a <"pre-filter"> for mechanical filtration), and I just use any combination of coarse sponge, floating cell media, <"Eheim "coco-pops", Alfagrog, Hydroleca etc."> in the media baskets.
I will do a water test to check before I put anything in. It sounds like I could have done the cycle with just the tropica soil then? I've got some tetra safe start which I'm going to add when I add the first few hardy fish.
On behalf of your fish, please don't do that. There is no such thing as a 'hardy' fish when it comes to ammonia toleration.
Have a look at <"Dr Timothy Hovanec's comments about Bacterial supplements">. In terms of "cycling" you don't <"need to add ammonia"> etc (it may actually prolong the time period when your tank isn't fish safe). You just need to <"plant the tank up and wait for the plants to grow in">.

It does away with a lot of the uncertainty <"surrounding water testing">.

cheers Darrel
 
Hi @Wookii I just did a test on the tank and you were right this soil does release ammonia, I'm shocked as it's reading pretty damn high! why is there no warning on the packaging? Ok I definitely won't be adding any fish, but am now thinking that this will in effect cycle the tank without fish so I can just leave it running? I don't need to do a water change, I can just leave it to cycle right?

I'm so glad I asked on here, the waters been in the tank over a week now. I suppose I can add the Tetra Safe Start to speed thing up right?

Also @Wookii I notice you are in Nottingham too, where do you get your plants from?

thanks @dw1305 for the link I will definitely have a good read when I get the time.
 
I don't need to do a water change, I can just leave it to cycle right?

No, precisely the opposite - you need to do loads of big water changes, 75%+ a day for a week or so, then every other day for a couple of weeks. Ammonia is the enemy, and removing it will help you avoid an algal outbreak and reduce the chance of melt.

I'm so glad I asked on here, the waters been in the tank over a week now. I suppose I can add the Tetra Safe Start to speed thing up right?

You could add it if you have a bottle already, but I personally don’t think it does anything to aid cycling.

Also @Wookii I notice you are in Nottingham too, where do you get your plants from?

I have historically bought plants from Aquarium Gardens or Aquasabi (before Brexit stopped them shipping to the UK). I’ve bought some from Proshrimp as well but their quality is hit and miss.

Now I tend to prefer to buy plants from members on here in the classifieds. They have the advantage of already growing well in submerged form, and I’ve had some incredible quality plants.
 
@Wookii I have nothing the tank at the moment apart from the Tropica soil and water, surely the ammonia being released will start the nitrogen cycle? What do you mean by melt?
 
@Wookii I have nothing the tank at the moment apart from the Tropica soil and water, surely the ammonia being released will start the nitrogen cycle? What do you mean by melt?

Oh, I hadn’t realised you hadn’t planted yet. If you are running it dark, then there isn’t the same immediate need, but I’d still do the water changes. The cycling on needs a very small amount of ammonia present. High levels may be detrimental (@dw1305) might be able to confirm.

Getting it planted up ASAP will help with the cycling and ammonia removal.

By melt, I meant melting and decay of plant leaves which high levels of ammonia can cause, as I assumed you’d already planted the tank.
 
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If running it in dark for few weeks there may not be a need to seed the new filter media, 4-6 weeks is all it takes and was the method TGM ( The Green Machine) used - it doesn't show in the vids. if less than 4-6 weeks I would fill the new tank with water, prime it or wait 24hrs, them just squeeze/clean active sponges in new tank water (unless they are really dirty), if really dirty, clean them put back in old tank wait a few days then use them.
 
Hi all,
surely the ammonia being released will start the nitrogen cycle?
While you don't have any plants you <"can turn the light off">, but carry on changing some water. As soon as you plant the tank the plants will start removing the fixed nitrogen (NH3, NO2 and NO3).

Just ignore everything you've read, or been told, about aquarium filters, <"ammonia and cycling"> none of it is right.

cheers Darrel
 
To be honest here and if there's nothing in the tank(live stock or plants) I'd just hook the new filter up to it and keep doing water changes to keep ammonia levels to ~1ppm. If you already have some tetra start then add it, won't do any harm.

And before I get pounced on, even Dr Timothy Hovanec suggests ammonia levels less than 5ppm are safe for bacteria, although I wouldn't risk levels that high.

When you come to putting plants in just make sure the ammonia levels have dropped to zero, or do some big water changes to make that happen.
 
Thanks for all the replies, I must admit I'm even more confused than ever now. Why do I need to do water changes to remove ammonia? Surely I should let the Nitrogen cycle take care of that? There's nothing in the tank apart from the soil and water so no real rush, the waters been in there a week.
 
Hi all,
Why do I need to do water changes to remove ammonia? Surely I should let the Nitrogen cycle take care of that?
The traditional view of nitrification (<"cycling">) in <"aquarium filters, isn't right">. The bacteria, that needed high levels of ammonia and carbonate hardness, <"don't actually occur in aquarium filters"> and nitrification is carried out by an assemblage of Ammonia Oxidising Archaea (AOA) and Nitrospira bacteria, some of which are COMAMMOX organisms that can <"directly oxidise ammonia (NH3) to nitrate (NO3)">.

Scientists have found all these novel nitrifying organisms by searching for gene sequences and they've also found that the assemblage that develops in aquarium filters is characterised by <"a stable core of microbes that are favoured by low ammonia levels">.

As soon as you add plants in you have <"plant/microbe nitrification">, and that is potentially a lot more effective than "microbe only" nitrification, there are a number of reasons for this, but a major one is the net <"positive oxygen production of plants">, because nitrification is an <"oxygen intensive process">.

cheers Darrel
 
Any reason you can't run the old filter temporarily on the new tank? I'd do the setup, get your 'scape' sorted, add plants - let the tank run a few weeks so you have active plant growth. Then double check your ammonia is ok from substrate and move the old filter and fish over. You can remove the old filter later once the tank is well established.

I did mine slightly more gradually in that I set it up, ran a few weeks, then moved some media from my old tank along with some of the fish. Then added more fish and the old filter. Does depend a bit on your stocking level and type of fish though. I was doubling volume so a slightly bigger increase than you.
 
The old tank is a juwel so fixed filter and I need to keep that in the tank as it's well established, with lots of plants, fish and shrimp. The new tank is a fluval so I can move the filter where I like.

Something else I mentioned is that I want to add some fish before plants as I have 3 gold gourami who constantly hide in the current tank and this is because they were constantly attacked by a Molly for a while. Before the Molly was in there they would be social fish and would hang around the surface but since the Molly attacked them they constantly hide at the bottom of the tank. They have been like this for about 6 months since the Molly was removed so their behaviour isn't changing. My aim is to add them to the tank once cycled but there won't be anything for them to hide behind for a while so it will hopefully reset their behaviour.
 
Today I tested the water and it was 0 ammonia, 0 nitrites, so I'm going to put fish in there tomorrow with some start start. The Tropica soil only required 1 water change to sort it out.
 
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