Gavin1980 4 Report post Posted October 18, 2018 I currently have a Eheim 600 filled with 2/3 of Seachem Matrix on my 4x2x2. I only have one 21cm Coal Grunter in the tank. Due to work commitments it has been 3 weeks since the last water change. I always do a 50% water change. My nitrates are now through the roof at at least 80ppm. I normally do a water change every week. Regardless, I still seem to always be at the higher end of the nitrate levels. I have considered upgrading to a Eheim 1500 or Fluval FX6. Would upgrading to a larger canister filter help keep the nitrates down provided I use around 2/3 Seachem Matrix in it? From what I have read about the Seachem Matrix, it's meant to allow anaerobic bacteria to grow inside the media to remove the nitrates. However, a large cannister has a high flow rate which means it wouldn't be very efficient at this process which means the upgrade to a larger filter may not make much difference and be a waste of money. What's everyone's thoughts? Share this post Link to post Share on other sites
Rod 189 Report post Posted October 19, 2018 One fish.....large tank.....High nitrates??? Suggest you clean canister and reduce feeding + do water change Share this post Link to post Share on other sites
A.M. 3 Report post Posted October 20, 2018 I don't think that a larger canister will help you. Not too convinced that there'll be a good amount of effective anaerobic area in the matrix inside a canister filter. Definitely try what Rod suggested. Perhaps a refugium with lots of plants will work better than a larger canister? Or maybe have a look at some nitrate media for short term use? (Not sure how well they work though). Share this post Link to post Share on other sites
Delapool 57 Report post Posted October 20, 2018 If he would leave floating plants alone could be worth a try. Threads I’ve seen on filters to remove nitrates have generally been specifically setup as slower flow I think. Share this post Link to post Share on other sites
