Thread: New Filter Issues

Hi folks, my husband and I are new to fish keeping as we inherited our pond when we moved into our house earlier this year. By my calculations the pond is about 5,500 litres and contains 12 fish with a mix of several koi and assorted goldfish. The filter system we had was a Heath Robinson set up so on the advice of a couple of local Koi Companies we have changed it to a Bioforce Revolution 9000 earlier this week. Unfortunately over the last couple of days the ammonia levels have been spiking (nitrite still seems ok), so I’ve added some started bacteria gel for the filter and temporarily stopped feeding the fish is there anything else I should be doing.

hi & welcome to the forum,

In my humble opinion you need to carry out a partial water change, perhaps 25% to start with.

I heard this little saying years ago, and have always believed in it:

"The solution to pollution is dilution"

Hope this helps.

Wise advice there from Brian, I can't offer anything other than doing that first and keeping the feeding down as said already!!

What are you using to test and get your results, to help others give further advise, the actual figures of the tests would be handy, as ok is leaving a lot of guesswork

Was this a routing test or were the fish indicating something was wrong?

Originally Posted by dbs

Wise advice there from Brian, I can't offer anything other than doing that first and keeping the feeding down as said already!!

What are you using to test and get your results, to help others give further advise, the actual figures of the tests would be handy, as ok is leaving a lot of guesswork


Was this a routing test or were the fish indicating something was wrong?

I’m using a couple of ammonia tests one by Colombo and the NTL labs, the Colombo test is showing between 0 & 0.5 mg/l and theNTL labs between 0.2-0.5. It’s just a routine test as the fish seem to be fine. I’ve done a nitrite test today with a test from API and that’s coming back as between 0-0.25ppm.

i know it’s down to the new filters but I’m beginning to wish we hadn’t updated them as our figures were fine using the old ones, but because that was a Heath Robinson set up it was difficult for us to maintain.

Ah okay, yeah i get that now, well moving forward as you must, all you can do is stop the possible causes and try and change the water through dilution as said by others, you need ammonia to get the filters working so I'd personally just keep doping what you are, keep testing and keep a close eye which you are too already... I hope you are seeing the levels drop