Pre Filters

[macksjay]

Hello I have just bought the Eheim 2217 for my Rio180 and I noticed you can get a prefilter for it. Would this be worth getting.

Thanks for any help

 

[Verminator89]

The prefilter is just an extra layer that stops the finest and biggest particles of gunk getting inside. Its beneficial to have as its extra filter media for bactera to colognise, you just have to give a rinse a little more often as it can clog quicker than the rest of the filter and thus reduce flow.

I have a prefilter on all my filters, but it is optional.

 

[waterdrop]

I've always wondered whether the dividing line between when a prefilter is useful or not was whether you were able to be a "daily futzer" in your aquarium. Obviously if you could grab the prefilter sponge and rinse it on a very frequent basis, it would help your filter box not become clogged as soon, but the intake would continue to operate effectively.

It has always seemed to me that the rub would come if you were away on trips or otherwise neglected your prefilter duties. I guess the frequency with which the prefilter would need flushing would obviously depend on the amount of debris. How often do you find you need to give yours a rinse, Vermin?

There must be particular situations where a prefilter is particularly helpful? I believe in practice they are used fairly rarely.

~~waterdrop~~

 

[OldMan47]

I add a prefilter function to many of the tanks where I have fry growing out. I do not buy the proprietary Eheim version though. I have found it as easy as can be to slice a simple slit in the end of a sponge meant to be used in a filter and then slim that over the inlet tube on a filter. It effectively saves my fry from even the tiniest fish, Heterandria formosa, and acts as an extra biofilter for the tank. I can even move it to another tank if I need an instant cycle for, you guessed it, new fry.
My filter sponge laying on my desk top waiting to be used.

The sponge in place after about a month in my Heterandria formosa tank

I am sure the Eheim prefilter is prettier, but mine cost very little to make. It merely required a sharp knife to make a slit and a piece of filter sponge to make it from. Sponges for replacement in HOB filters are sold in 2 and 3 packs for only a very few dollars.

 

[waterdrop]

Thanks OM, interesting! I had some young neons just a while back that were small enough that I worried about them going up the intake tube in my Q-tank. I had an extra mesh filtermedia bag, so I just put that over the intake. Actually, an interesting thing happened: I left it on quite a while (some months) and one day I noticed reduced flow from the filter. It turned out the mesh bag had become incrusted with biofilms, debris, whatnot, and was "stuck" to the intake basket. I just pulled it loose and full flow returned, but it was an interesting observation.

Your post reminds me that I could have used a sponge instead of the mesh bag and it would have been -less- likely to clog up I believe. Secondly, and not really related , the picture also made me suddenly realize I should check out the little boxes of replacement sponges in the filter row at the LFS to feel the different sponge textures: I rather prefer having small sponges that are a bit rough in texture for hand cleaning aquarium things and that white one in your picture looks just right!

WD