Ehiem 2327 Blocking UP

[Dee123]

I have a well established (over 2 years) 300 liter tropical fish tank, with about 30 small (max 5cm long) assortment of barbs, Neons etc and a variety of plants.

I do a normal water change (70 liters every 2 /3 months NO2 levels is virtually 0, and NO3 is always Kept to a minimal as possible using Tetra Easy Balance).

I am using a Ehiem 2327 Thermo Wet&Dry canister filter. The filter has two trays which are both filled with substrate in the first year I only had to clean the filter once (after about 8 months) and then all I did was take one tray out completely empty the substrate into a bowl and wash with water from the aquarium.and then replace it.
But I have noticed that over the last 9 months I am having to clean the filter very regularly (about once very 2 months) because the substrate gets blocked up heavily with bacteria and as a result the Wet&Dry stops working and it only works as a ticking canister filter after a clean (like mentioned above) all goes back to normal.
What’s is going wrong? What is an acceptable lever of bacteria in the filter and why is it slugging up?
Thanks

 

[fraservet]

try putting a pre-filter on the intake pipe

 

[BobK]

Key question, what types of media are you using and in what order?

 

[jbennett]

Aren't you supposed to replace half the media after 12 months to replenish the old bacteria with fresh?

 

[Dee123]

Hi, and Thanks for responding

try putting a pre-filter on the intake pipe

are there any recommended Eheim pre filters to be used with this model, the only sort of pre filter was the foam at the very beginning of the inlet pipe which I removed 8 weeks after the filter was installed as instructed in the manual.

Key question, what types of media are you using and in what order?

Only one type in both trays (that’s what the manual say to do) Eheim EHFISUBSTRAT.

Aren't you supposed to replace half the media after 12 months to replenish the old bacteria with fresh?

sorry I forgot to mention I did replace one tray with new media about 12 months after.

 

[fraservet]

do a search for eheim pre-filter, or look on the eheim website.

 

[rvm]

If you use a prefilter on a Wet/Dry, the problem you'll come across is as the prefilter gets clogged the Wet/Dry action will eventually stop. So you need to keep an eye on it and keep it pretty clean.