Fishyfishfish Fishyfishfish
  • Just popping in
  • Just popping in
  • Joined: 31/5/2018 8:25
  • Group: Registered Users
  • Posts: 16
  • 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
  • Coldwater Adviser
  • Coldwater Adviser
  • Joined: 17/10/2014 11:20
  • From -
  • Group: Registered Users Basic Membership Advisers
  • Posts: 483
  • 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
  • Just popping in
  • Just popping in
  • Joined: 31/5/2018 8:25
  • Group: Registered Users
  • Posts: 16
  • 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.