Filter media

[dan the whaler]

Hi,

I've been lurking for a while, so here goes with my first post.

I've just bought my son a tank "kit" (100L about 22 gallons) with all the accessories supposedly in it. The filter media though is a single piece of sponge about 4 inches square by about 2 inches thick (medium to coarse sort of texture). There's about 3 x this volume still unused in the filter box stuck on the side of the tank (internally). He wants a tropical freshwater community tank with plants, so my question is, what other filter media should we use for this tank? My guess is a coarse filter, fine filter and maybe some ceramic or similar as a bacterial substrate, does this sound ok?

Also, does anyone have any information about exactly what kind of sponge/foam to use? Most the vastly overpriced stuff in the aquarium store looks like things I could get from a dressmaking shop, or I could cut down large sheets of foam intended for koi carp pond filters. It all looks the same sort of stuff to me.

Currently, there's no fish in the tank, but the filter is running to clear the murky water caused by the gravel we added, the foam block was too coarse, so we've sucessfully used an old sports sock! - I'm not suggesting that I'd use this when the fish are introduced, but I reckon that there's plenty of cheap media that could be used of various sorts of inert polymer wadding rather than the "rip off the uninformed" approach of many of the aquarist manufacturers.

20 years ago I was a post-grad marine biologist and I made effective external trickle filters using all sorts of spun polymer and wool-like materials. I've not had a tank since then, so would like some advice as to avoid trial and error myself at least at first!

Paul

 

[Mookka]

Nice

I started out with a kit just like the one you just bought for your son! Anyway, make sure to put some type of chemical filtration in to suck toxins out of the water (carbon). The bacteria can grow just fine on your sponge but you can get a finer filter if you like. hope this helps!

 

[Raskolnikov]

I find coarse sponge to be the only media necessary in my filters to maintain crystal clear water and complete nitrification, even with some heavily stocked tanks.

 

[happychem]

I'll use carbon only in certain circumstances: vacation, removal of meds after illness, providing impeccable water during a non-medicated illness treatment, because for some things meds are a waste of money and time.

If you've got experience making an external trickle filter, have at it! It'll probably be as good or better than most comercial stuff.

You can buy bulk polywool from aquarium shops pretty cheap. I don't know how much it would cost at a dressmaking shop, but it's already pretty cheap. It works very well for packing a filter, the only downside is that it's a PITA to clean.

You can buy bulk aquarium filter sponges, I just buy the largest available AquaClear sponge and cut off what I need. This is more expensive than the poly-wool/filter wool route, but they're sooooo much easier to clean, just give them a couple squeezes in old tank water and voila!

This tends to be cheaper than buying the made-to-fit sponges. I wouldn't waste my money on filter cartriges. I've used them when they came with a tank that I bought used, but I consider them a waste, they're costly and, as you pointed out, leave a lot of unused filter space. Just pack it with as much low cost filter sponge or polywool as you can fit.

 

[dan the whaler]

Many thanks for the advice folks, nice to hear I was on the right lines. It also puts the commercially available products into perspective.

I wasn't intending to use carbon as it removes trace elements that the plants will need. The external trickle filter will have to wait for another tank, I've plans for a marine reef tank and will probably make a protein skimmer for it first.

Thanks again :thm: