Fishyfishfish Fishyfishfish
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  • Posted on: 25/1 13:50
Ammonia spikes every time I replace filter media #1
Hi folks

This is becoming a major problem for me and I don't know why it's happening.

I have a 125l Fluval tank with a Fluval U3 filter. The central compartment contains Biomax, and each outer compartment contains a strip of sponge and a carbon/poly pad.

Every time I remove the old clogged up carbon/poly pad I get a spike in ammonia. I only ever change one carbon/poly pad at a time and only ever when they become filthy (usually every 8 weeks ish). I soak the new carbon/poly pad in old tank water in a jug for about 10 minutes beforehand

I'm actually scared of changing the other side because I know I will get a spike in ammonia. The only fish in the tank currently is 5 platy and 1 cherry barb so it's not overstocked.

I can't think of anything else I can do to prevent it from happening.
fcmf fcmf
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  • Posted on: 25/1 14:03
Re: Ammonia spikes every time I replace filter media #2
I used to have a Fluval U2 myself, so I can recall what it looks like. That is odd that removing that quantity of filter media is resulting in that effect, as it is much less than the >1/3-max recommendation that is generally considered safe to remove, and especially as you're understocked. Are ammonia levels definitely fine the rest of the time?

There isn't actually a need for the carbon/poly pad, except for if wanting to remove medication from the tank. What I did with my Fluval U2 was to insert extra foam into it in lieu of the carbon/poly pads, and then didn't need to change them anything after that - just the gentle squeeze into being-discarded tank water (and a jiggle of the Biomax in similar fashion). You could remove one carbon/polypad, ensure that you spend the next week or two doing extra water changes, then remove the other and add in extra foam/sponge once they're both gone, continuing with extra water changes for another fortnight or so after that. To be extra safe, you could dose with Seachem Prime during each water change to reduce the toxicity of any ammonia for the following 24 hours, and possibly even coat the extra foam/sponge in Tetra Safestart or Dr Tim's One & Only which are one of the few of the bacteria-starter type products with some evidence of effectiveness.

Hope that helps.
Fishyfishfish Fishyfishfish
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  • Posted on: 25/1 14:16
Re: Ammonia spikes every time I replace filter media #3
Quote:

fcmf wrote:
I used to have a Fluval U2 myself, so I can recall what it looks like. That is odd that removing that quantity of filter media is resulting in that effect, as it is much less than the >1/3-max recommendation that is generally considered safe to remove, and especially as you're understocked. Are ammonia levels definitely fine the rest of the time?

There isn't actually a need for the carbon/poly pad, except for if wanting to remove medication from the tank. What I did with my Fluval U2 was to insert extra foam into it in lieu of the carbon/poly pads, and then didn't need to change them anything after that - just the gentle squeeze into being-discarded tank water (and a jiggle of the Biomax in similar fashion). You could remove one carbon/polypad, ensure that you spend the next week or two doing extra water changes, then remove the other and add in extra foam/sponge once they're both gone, continuing with extra water changes for another fortnight or so after that. To be extra safe, you could dose with Seachem Prime during each water change to reduce the toxicity of any ammonia for the following 24 hours, and possibly even coat the extra foam/sponge in Tetra Safestart or Dr Tim's One & Only which are one of the few of the bacteria-starter type products with some evidence of effectiveness.

Hope that helps.


Thanks for the quick response fcmf, appreciate it.

Ammonia isn't usually an issue other than when I'm changing the media, and unfortunately, I've been trying to solve this issue for weeks now without success.

I've tried to do away with the carbon/poly pads but I can't seem to find a compromise. Putting in another sponge pad won't work because it ends up being too thick and cutting the sponge in half length wise is messy and never works. Also the sponge is quite 'holey' and isn't fine enough so the biomax ends up getting filthy really quick.

I actually do a double dose of prime along with water changes whilst the ammonia spike happens but that is no long term solution. I will look into those bacteria-starters though.
Fishyfishfish Fishyfishfish
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  • Posted on: 19/2 7:45
Re: Ammonia spikes every time I replace filter media #4
Looking for some further advice with this, as it's still an issue.

The situation has changed in that I added 6 cardinal tetra at the end of January, they seem to be doing great but it's Cherry the cherry barb who I've seen flicking off objects a few times.

Also, I was using a fluval mini as a supplementary filter alongside the U3, but it was unbelievably noisy. So, last week I removed it and replaced it with a U1 (I like to have a spare filter for quarantining). Now I know I lost some bacteria when I removed the mini but I wasn't expecting it to cause any issues.

For now I'm doing water changes with double doses of prime, and I hope things will settle down but I'm concerned that I may be overstocked at this point (1 cherry barb, 5 platy, 6 cardinals). Am I?

Thanks for the advice.
fcmf fcmf
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  • Posted on: 20/2 15:04
Re: Ammonia spikes every time I replace filter media #5
The current stock you have definitely is not overstocking for the size of tank you have - the tank ought to be able to stock a shoal of 8-10 cherry barbs, the 5 platy and 8-10 cardinals (and the increase in numbers of cherry barbs and cardinals might help these shoaling species feel less stressed and possibly even the flicking behaviour of the sole cherry barb). I'll explain later how this would need to be done, though.

In terms of your current problems, I think it would be worth going into some LFSs and checking the consistency of their foams for different filter brands - if you can find one that would "fit the bill" for the part of the filter where the carbon/polypads were, and possibly even in the Biomax compartment in lieu of the Biomax, then hopefully you can cut/trim/shave it to size. It might even be that you chop or double up the current foam in order to best accommodate this extra foam - as long as the existing foam remains in there, it doesn't matter how it's placed (cut/folded, etc).

The addition of the 6 cardinal tetra at the end of January will have increased the bioload considerably, because essentially the beneficial bacteria which you had will have to process the waste/ammonia of twice the number of fish. That may have caused a mini-cycle or even a full cycle to occur, which may account for ongoing ammonia presence.

The best way to add new fish is to quarantine them in a separate tank for a month or so, with a portion of existing filter media (which will contain the beneficial bacteria) transferred into the quarantine tank's filter - it's generally safe to remove up to 1/3 of existing filter media. In the main tank, replace the being-removed portion of media with new media, ensuring that the existing media has direct contact with the new media to "seed" it with the beneficial bacteria. Once the quarantine period of time is over, move the quarantine tank filter into the main tank as well as the new fish, so that all the beneficial bacteria required to process existing and new fishes' waste is in the tank. You could then either have the quarantine tank filter in there on an almost-permanent basis, to easily remove and put in a quarantine/hospital tank as required or else you could gradually remove a small portion of media from it every few weeks, so that the main tank isn't in danger of losing too much of the beneficial bacteria at a time (which processes the waste of all the fish), before eventually removing it and just keeping the main filter in the main fishtank.

When you replaced the Mini with the U1, did you transfer the media from the former into the latter? If so, that oughtn't to have had an adverse effect. If you didn't and instead discarded the Mini's filter media, that may also have caused ammonia to be present/increase, in addition to the extra ammonia from the new cardinals.

Continue doing water changes with double doses of prime, perhaps every alternate day or whatever it requires to keep ammonia at 0 (and nitrite), and hopefully this will get you "back on track", in conjunction with the filter media as described above. Don't even consider adding any new fish until you get this process under control for at least a month with 0 ammonia daily. Only if you manage to get all under control for at least a month, then consider adding stock as described above - you could perhaps quarantine and then add 5 cherry barbs in the first instance, then if/once the main tank seems to be settled with stable 0 ammonia readings from that, then consider perhaps 3 more cardinals and 3 more cherries in the second instance (the Mini or U1 ought to support each of the two batches of 5 or 6 fish at a time during quarantine in the way I've described).

Hope that helps.
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  • Posted on: 21/2 10:34
Re: Ammonia spikes every time I replace filter media #6
Thanks for the info fmcf.

The way I have it setup is the U3 is the main filter for the tank, then the mini/U1 is the supplementary filter. This supplementary filter gets taken out whenever I buy new fish, and ends up in a 24 litre holding tank whilst I quarantine the new arrivals. The Cardinals were quarantined for just over 2 weeks. Then the supplementary filter goes back into the main tank.

I think what hasn't helped this time is that I had the issue with ammonia after replacing some of the filter media in the U3. With hindsight perhaps I should have left it a few more weeks before adding the Cardinals. When I swapped out the mini for the U1 I didn't put the sponge from the mini into the U1, so I obviously lost some beneficial bacteria. So again, bit of a school boy error, but I expected the U3 to be able to handle it.

I'm not adding anything else for months now, I need to get on top of it before adding anything more. The sponge situation is also problematic in that I have tried various ways but never manage to get the sponge to fit. It's either too thin or too thick. The sponge that goes in alongside the carbon/poly pad is too thick to cram in twice and I really don't want to start slicing through sponges to try and get them to fit. It'll only be a problem when I come to remove another carbon/poly pad, so I've got time to find a slution I hope. Suggestions are welcome!