Sulphur smell from NFP509 Nitrate Filter

Question:

I have had a nitrate NFP 509 running for about 6-8 months, it has done a great job but it filled with dead bacteria so i cleaned it out. The problem is now that it has a sulpher smell and i can't get rid off it while its running. Any ideas ?

Answer:

You do need to clean it out from time to time to remove any dead bacteria.

The sulphur smell suggests that you are running it too anoxic, (low oxygen) and you need to either increase the water flow slightly or more probably to reduce the amount of alcohol that you feed it every day.

As the level of nitrate in the tank falls there is no need to have so many bacteria to cope with it and so if you supply less food them some will die off. You must play with the level until you get something which works with your fish load.

If after cleaning you have started from scratch on the flow rate you will find that it will mature very quickly (unless you used tap water to clean it) and so you can increase the flow again quite quickly, much faster than when first starting.