Cleaning / Replacing Hamburg Matten Filter

[jameson_uk]

I setup a HMF in my hospital / quarantine / grow out tank a couple of years ago and it has done great but the sponge has got to the point that it is no longer holding it's shape and keeps collapsing into the area behind it where the heater lives.

I normally replace sponges that get to this stage but it has me thinking
a) should I have been doing better maintenance on the sponge (I have largely left it untouched)
b) when I replace it, is it worth leaving the old sponge (or at least some of it) behind the new sponge as well as squeezing it out to prevent a full cycle again

 

[mort]

How often they need cleaning depends on how much detritus there is. I was once told "if water still goes through it then leave it a while longer". I must admit I've only cleaned mine when breaking the tank down because they have a huge surface area and seem to do a better job the longer you leave them.
If you have a low bioload or no real bioload then a quick squeeze of the old one to "seed" the new should do the job. If you have a higher bioload or want to be on the safe side then putting a piece behind the new filter is a good idea.

 

[dw1305]

Hi all,

a) should I have been doing better maintenance on the sponge (I have largely left it untouched)

Try washing it out with a garden hose (out of the garden etc), it will get rid of a lot of the dirt without destroying the structure of the sponge. If it is still saggy after that you will need to replace it.

cheers Darrel