Not necessary to replace biomax as often as recommended, IMO.
On my Aquaclear 50 ... I have taken to utilizing a sponge pre-filter on the intake tube (which is simply a smaller Aquaclear 20 sponge with a slit cut in it), then I run dual sponges with 1 biomax to top things off. I've chosen to do this for several reasons.
The sponge pre-filter helps to keep debris from.....
- More readily fouling and clogging the porous structure of biomax ... it's good to keep your bio media as debris free as possible so the nitrifying bacteria doesn't have to compete with debris to survive
- It also keep debris from fouling the intake tubes and impeller
- And it keeps debris from clogging and reducing flow through the bottom sponge, which can cause the media basket to float (not a problem at all when sound maintenance is carried out)
On occassion, I also lightly 'swish' the biomax in used tank water.
If you're going to utilize a sponge pre-filter ... you should rinse it in used tank water regularly. I coincide it with my weekly
water change. Given that the sponge will release trapped debris when the filter is turned off and suction ceases, I immediately remove the intake tube with sponge attatched and place it in a container of used tank water to be 'swished' a bit later. I then proceed to remove the floating debris that is released by the sponge with my vac before it sinks to the bottom ... I then continue with my water change.