Hi guys-
Everything seems to be doing okay, but I had a question regarding filter changes. I have one of theose twin HOB's for my 55g, and I've always completely changed the filter materials( bag and act charcoal) but I keep seeing that you guys suggest rinsing it in a bucket of tank water. Is this appropriate for HOB filters? Should I change them once in a while? I was changing one at a time and just rinsing the other in the tank water. How often should I change water and how much? Right now I have 2 4-5" angels five jumbo danios (2") and two waterfall shrimp. The tank is pretty much cycled so I'll probably change some more water on Wed. So far, I've been doing about 10% every week.

The object of rinsing the cartridges in tank water is to keep the chlorine in tap water from destroying your bacteria colony. If your filter came with a large cell sponge that slides in front of the cartridge you can rinse the sponge in tank water and rinse the cartridge in tap water, this is what I do. You are still getting the same effect by changing or cleaning only one of the cartridges at a time. I use the sprayer hose on my sink to rinse out the cartridges, they can be re-used several times before replacing them, I keep using them until they will no longer stop the big chuncks of "stuff".

Thanks-
That clears it up., I actually have well water so the chlorine is a moot point, but it makes sense. Thanks for the tips.

also, what make and model of HOB are you using? Do you use activated carbon or other chemical filtration media?

It's just the standard Tetra Whisper twin cartridge that use activated charcoal that comes with the standard 55 g starter kit.

Ok,

http://www.tetra-fish.com/catalog/product.aspx?id=577 This one...

I would consider adding something like a ceramic "cell pore" type material to give you more surface area for biological filtration. I wouldn't replace the media bags, just rinse them in dechlorinated water. I also wouldn't bother with carbon in that filter (unless you are wanting to do something specific like remove a medication from the water)

That's the exact one I have on my 55gal, it comes with sponge inserts for in front of the cartridges(outflow side), and Seedy, the filter cartridges come with charcoal already in them.

I checked and you can also order cell-pore media slabs that fit the cartridge slot...

Do these have the "media bag" type cartridge with the clip on top, or are the "ready made" like what you find on an Emperor?

I ask these questions because IMO you can get a lot better performance out of just about any HOB filter with a few Do IT Yourself "tweaks"...I don't think I have a single HOB that I run "stock" anymore...almost everything now has either extra cell-pore, special purpose media (like peat for my soft water tanks), etc...I even have a modified aquaclear that now sports a biowheel...I also run almost completely carbonless.

The cartridges have the clip tops that are designed to be rebuilt, they even sell rebuild kits for them. On my old cartridges I have even used the toes of pantyhose to cover the frame. LOL ;) One of the cool things about these is that you can put whatever you need in the media bag, I used to use ammonia pillows but when the "bag" they were in got torn I just dumped the crystals into the media bag.
I only leave the charcoal in them for about a month because I have read that after time the charcoal no longer absorbs the toxins and will eventually start leeching them back into the water.
So, why don't you give us some tips on how to tweek them up, maybe in DIY?

I do rebuild my own catridges- it's a lot cheaper than buying the pre-mades, but I didn't get the sponge inserts. Can I just buy them at my LFS, or do I need to e-order them? Should I keep changing them "every other" every two weeks? Thanks!