Ehiem Professional II 2026

[jc85]

Hi,

Just wondering for those of you using this cannister filter, does you guys change the substrate that is provided in the box? I read and heard that bio-ring will cause problem due to dirt stuck in it. What are the recommended substrate to use?

I was thinking abt this issue and have a thought. If I have 4-5" of C0 sna d in the cannister bottom, wouldn't that make it a DSB?

[dragon1188]

I used to put rings and coral chips in my 2026 2 years ago. Now I have junk all substrate. The 2026 is just a powerhead doing water circulation.

Don't use cannister for marine (whether FOWR or reef)...it will just convert all waste to nitrate, which is the hardest thing to get rid off. My NO3 level used to be 70-90ppm using cannister. Now I have converted to 25kg live rock and 3 power head on my 3' tank. NO3 level is now less than 15ppm....also less changing of water now (3-4mth once).

As for your idea of 3-4" of sand inside cannister...think the surface area is just too small!

[SpiderOne]

dragon1188 .

Ur nitrate level 70-90 ? its your great choice of coral chips and bio rings media. not the canister. im using a 2228 for a full reef . nitrate levels are perfectly fine.

Your tank had no live rock while u were using canister?

Powerheads dont get rid of Nitrate

Nitrate is not even close to the least hardest thing to get rid off.

DSB in canister is not feasible probably due to the constant disturbance by water flow not the lack of area.

My canister is purely mechanical and chemical . it has wool only which i take out and replace frequently and when i need chemical filtration it provides a convenient place.

† note the use of probablies where stated

†† No Sarcasm was used in the typing of this message. Any resemblance is purely Coincidential

[jc85]

Hi Tanzy, my main intention for my cannister is also for mechanical filtration and chemical since I had ~50kg LR adn a 5" DSB. Does that means that I should remove the substrate 1st until I need the chemical filtration than add the appropriate substrate?

[dragon1188]

Spider ONe,

You r right. The cannister is fine. Its the substrate. Using the canister for circulation is perfectly fine..even better than submerged PH, as cannister don't put that much heat into the tank.

But once you use coral chip or other biological filter inside the cannister, it became a NO3 factory via aerobic process.

LR is the one that reduces NO3 but without good circulation by PH or cannister as PH, they won't be effective. Even DSB won't work effectively without good circulation. Read an article some time back that effectiveness of DSB depends on nutrient exchange between DSB and water body. Assuming DSB has achieved anaerobic condition, effectiveness is dependend on void space between grain (ie. grain size) and movement of water (ie. circulation).

In short, good circulation and surface agitation offers great benefits to the marine tank.

my 2 cents,