Which Filter Media

[craig855s]

After a quick foray into the marine world (Which I didnt enjoy as much as I enjoyed keeping tropicals, hence the marines are gona and im back) I'm returning to tropicals and plan on getting a Juwel trigon 350 (maybe 190) in the very near future. Whilst owning a marine tank and frequenting Ultimate reef tyhe general consensus amongst the reefers was that Bio balls (black plastic spheres) although helpful for growing n-bacs on, also collect detritus which then stays in the tank to become nitrate, which then builds up.

They also say filter sponge does the same, they say to just leave the live rock to deal with the N-bacs (I think maybe ceramic rings could do it in the trop world?)

but then that leaves the detritus, how would this be dealt with if its not getting caught in the filter media? high circulation? A skimmer? Gravel vaccing?

I want zero nitrates in my tropical tank when i get it going, so i dont want detritus sitting in the filter sponge, so im thinking if i fill the filter with ceramic rings and vac the gravel regularly (although i actually want a fertiliser and sand subtrate for planting) will this keep the nitrates down? Or will a sponge media do the job just as well, so long as its rinsed in tank water very regularly (i used to do it once a month, but my old tank had an algae problem, maybe more frequent rinsing would have helped)

 

[saltynay]

Your looking for mechanical filtration of the detritus but you don't want it to rot correct and you want high biological filtration?


I would use a fluidised sand bed filter which I wrote the maths for here but if you looking to set-up an external then I would do:

Input -> circular film made of women tights stretched taught -> Polishing wool -> fine wool -> Bioballs -> fine sponge -> polishing wool ->output

You want to remove the tights and polishing wool every couple of days and clean them as its not biological filtration it doesn't matter if you wash it in tap water.

 

[OldMan47]

Welcome back to our world Craig.
You are correct, as are the marine people, that many forms of filtration will accumulate matter that eventually will decay and create nitrates. The only way to avoid that is to clean your filter media regularly. All of my best mechanical filtration schemes do indeed accumulate some material which will eventually decay to produce nitrogen compounds, otherwise they are not doing their job. The only way to minimize the effect is to clean the media before it has the chance to begin the decaying of trapped organics. There is no such thing, in the freshwater world, as a filter that can trap suspended materials without creating the potential for decay into nitrates. I suspect the same could be said about salt water although I am far from expert on marine water chemistry.