[Walshy]

I have been running a reef tank now since Jan 06 with pretty good results, corals growing and no fish losses except an over protective clown that in its over protective state after laying eggs lept out of the tank trying attack my hand during cleaning

The tank is an Aquamedic 120 Percula bowfront tank - German made with an inbuilt trickle fitler at the back, skimmer and return etc. I do use carbon and phosban in the return. I don't overfeed but still get nitrates around 10-15 even with a weekly water change of about 60 liters. All other params are fine.

I have read various views on trickle filters with bio balls, most say get rid others state no evidence that they are a bad thing (Delbeek and sprung - reef aquarium).

So I'm looking for advice - I do have large amounts of live rock in the tank so should I remove the bio balls and replace them with rock - this part of the tank is covered without light?

[Reefland]

Hi Walshy,


The problem with this type of media is that it traps waste. If you pull out a few of your bio-balls and you can see waste built up in them then they are contributing to the nutrients. So this leaves you with the option of cleaning them often which is troublesome and therefore not worth it. I would slowly begin to remove them over the course of a few weeks.

[Samper]

I'd replace them with rubble or rock or make a refugium out of the chamber. Definately remove them slowly over the next few weeks to begin making the transition.

[Hingeback]

I have a percla 120 normal fronted. I have never ( touch wood ) had a problems with nitrates. I put this down to putting course filter wool on top of the sponge before it flows into the trickle filter and also a layer of fine filter wool on top of the filter plate in the trickle filter section. This takes out large amounts of solid waste and therefore cannot create a problem in the trickle filter. You do really need good flow aswell to get as much of the waste in the aquarium through to the filter section for this to work well. The filer wool needs replacing every few days and needs to be kept an eye on.

If I did have a prob with nitrates I would without fail follow the above advice except that you would have to add more water to the aquariun as you would need to flood the filter section as you would still have a trickle filter but with live rock / rubble and therefore the same prob of high nitrates.

[Walshy]

I did used to have various types of filter media but again if you don't clean them regularly they become nitrate factories too. I think I would like to try and make the chamber into a refugium as they offer many benefits.

To do this though after I have removed the bio balls over a number of weeks I would appreciate any advice on the best method to do it with my tank:

1. I already keep chaeto in the main tank so have plenty to start a refugium.
2. The tank design means the water level is low in that chamber unless as advised I overfill and then flood the chamber - this could adversly effect the skimmer
3. I assume a refugium needs light and that part of the tank is covered by a simple lid which can be kept off but isn't pleasing on the eye and the noise level goes up

Thoughts appreciated - I can provide a picture if it helps?

[salt-rookie]

YES..ONE WORD ANSWER! These are Nitrate Factories!!!

[Reefland]

I don't know that this would be the best application for a refugium. So you have two options in my opinion.
1. Just remove the bio-balls and leave it empty.
2. Remove the bio-balls and add a little liverock in the chamber, so long as the liverock stays submerged in water.

[Hingeback]

The water level in the first chamber should not rise because the extra water will naturally flow into the next two chambers. If for any reason it does affect your protien skimmer you can either add the extension collar to raise the cup, or place something under the skimmer to raise it slightly. ( I presume you are using the aqua medic that came with tank ). I did not like mine, I seemed to be forever tweaking it to keep it running correctly and no matter what it only ever pulled coloured water out. I replaced mine with a deltec mc600 which pulls out thick foul smelling gunk and my reef has improved beyond my expectations since.

All the best.