How often have you read postings or emails from aquarists who complain about their bio-balls going bad? The quickest and most often suggested solution we see to this problem is to, get rid of the bio-balls, now! This is ridiculous. It is not the bio-balls contained in a wet/dry trickle or another type of biological filter that have gone "bad," but just like with an under gravel filter, it is the "lack of proper maintenance" that turns them into a nitrate factory.
Lack of Proper Maintenance
It is only when bio-balls, as well as other similar types of biological filtration mediums, are allowed to become dirty and encrusted or embedded with the broken-down matter or dissolved organic compounds (DOCs) that they then start to contribute to the accumulation of nitrate in a saltwater aquarium or reef tank system. There is no need to immediately trash or remove them, which should not be done in the first place because it can cause your whole system to crash; you just need to clean them up.
Once this has been accomplished, as long as this is the "sole source" generating the nitrate in the aquarium, with some water changes and by keeping to a good regular maintenance routine, nitrate and bio-balls woes in all likelihood will decrease.
One way you can test to see if it's time for a cleaning is by ruffling or lightly stirring up the top layer of the bio-balls. When this is done you will see gunk break loose from them. The only problem is that in almost all cases the mass of the organic matter settles in the bottom layer of the bio-chamber because it gets pushed down by the water dispensed into the filter over time. You can stir the bio-balls up from the bottom to see how things look, but be careful doing this. If the filter is running and the output water goes directly back into the aquarium without being filtered first, it can shoot a bunch of the gunk right into the tank. To prevent this you can place a micron-mesh bag that is fine enough to catch the organic matter as the water is dispersed into the tank. To assist with cleaning up any possible organic matter that may get into the aquarium while you are testing for, as well as performing a cleaning, attach a simple hang-on-tank canister filter for mechanical filtration and run it during and several hours afterward.
Before You Start Cleaning
- This is a procedure suggested to be performed only on aquariums that have been running for at least 4 months because the nitrifying bacteria have had time to develop a strong population, and in all likelihood, the bio-balls have begun to accumulate a substantial, but not an overwhelming amount of DOCs.
- As far as how often a cleaning needs to be done, if your system has been running for some time (say longer than six months) with no bio-ball maintenance at all, it may take a little time to get them cleaned up first. After that, you can determine when cleanings need to be performed based on how your system is set up and functions. After a while, you will know when to do it.
- Even though periodic bio-ball cleanings are important, this procedure may weaken the nitrifying bacteria population that keeps the ammonia/nitrite in check in an aquarium. Therefore, it is vital that you do it properly to avoid stressing your system and possibly causing new tank syndrome.