# Improvement to a HOB filter



## jaidexl (Sep 18, 2006)

The main thing is probably water level, I keep it high and topped off. I replace media with sponges too, as well as bags of ceramic bio-beads, but I've never used the intake chamber. I let them stay fairly gunked up to reduce flow and never over clean them. I have seen betta DIYs where they glued a plastic soap dish or sponge to the front (outlet), to diffuse some current. Pre-sponges on the intake help too. Moderate flow and minimal surface splashing, some agitation is ok. Coincidentally I have a 30gl temp tank running as a layover spot for a few fish and plant scraps, and to keep some filters running as I transfer them. I have 5 hobs running on it, some are trickling. I'm injecting co2 to help the scraps and test a new regulator, with a limewood diffuser I am getting 30ppm with 4-5bps, that's kinda crummy for a 30gl but I'd say pretty darn reasonable for having *5* HOBs on it including an AC70 and some big honking marineland looking monstrosity.


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## jdm68 (Jun 2, 2011)

I saw a DIY where someone used a cup with strategic cuts in it to divert the flow to the side to minimize the intake sucking up freshly filtered water. Looked a little ghetto but I like the concept.
jaidexl - What kind of sponge do you use? Could you post a pic of your setup? I'm not sure what you mean by never using the intake chamber. My idea is to fill completely the place where the media usually goes, from front to back, rather than just a small "sheet" in the middle of an open area.


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## GeToChKn (Apr 15, 2011)

The best HOB's are Aquaclears. No fancy inserts to replace all the time, just a big square box inside for media. You can buy bulk carbon/sponge/floss and cut them to fit inside. You can put bags of bio-media, peat, purigen, whatever you want inside. They are the best thing if you can't do a canister IMO.


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## jdm68 (Jun 2, 2011)

Thanks for the tip GeToChKn, but I don't really have any plans to buy a HOB. I've just got a few around that work so I will use them until I get something better. If I were to buy a filter, I'd have to go with a canister. I already have an older Fluval 305, so I'm familiar with how they work, just don't yet have a need for a new one if I can get away with HOB's for now... I will also probably be using HMF's or normal DIY sponge filters anyways so I don't know I'll even buy a can.


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## jaidexl (Sep 18, 2006)

I use whatever sponges I have stocked up, all aquarium related but not sure what brand, some were given to me. By intake chamber, I thought you were saying you'd fill the first chamber where the intake tube enters, like the left side of an aquaclear. I also like aquaclears best myself and I pretty much stuff all my hobs in the same fashion. One problem with stuffing the entire chamber of an hob that normally uses slip in cartridge is that it can exacerbate the issue of 'path of least resistance'. Those are usually designed where the back fills then gravity and pressure push the water through the cartridge into the front, if stuffed too tightly with sponges front and back, the water can walk right over them and go straight out without a lot if it passing through.

I can take a pic of my hob tank, anything specific you want to see there?


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## jaidexl (Sep 18, 2006)

Here's the temporary tank. Filters from left to right:
AC70 with stock inserts/ lava rock/ filter floss - Red Sea Nano with second hand sponge then biobeads in back chamber/ then stock divider - AC10 with sponge/ beads/ lava - Whisper 10 with beads in back / empty divider/ stock sponge in front of divider - Unidentified monster with lava/ big mesh sack (pool skimmer net) of old carbon then filter floss in rear chamber/ stock divider with built in sponges.











Floating scraps are pinned up front but otherwise a nice even current across the surface and down the face, not so great swimmers (angelfish, SAEs) can easily hover, plant scraps are springing forth.


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## jdm68 (Jun 2, 2011)

That is some major filtration you've got going on. 

I can imagine what you mean by the path of least resistance thing, that's something I'll have to look out for. I bought a big sponge block today(yesterday, technically), and I will be cutting it to size tomorrow(today,) once I clean out the "new" old filter casing and whatnot. I like your use of the pool skimmer net as a media bag. I'll post up a pic of whatever I come up with.


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## jaidexl (Sep 18, 2006)

jdm68 said:


> I like your use of the pool skimmer net as a media bag. I'll post up a pic of whatever I come up with.


Ha, ya that's all I could find at the moment, it's huge but I just needed to clear up some water in my 75 for a day or two, that net is the only thing that will fill that big filter compartment. Then I just added it here with the rest since the tank itself wasn't cycled enough to hold those fish. I should start breaking some of those filters down by now but I'm just lazy.


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## jdm68 (Jun 2, 2011)

jaidexl said:


> I should start breaking some of those filters down...


Meh, I think the tank kinda looks cool with a whole wall of filtration. Unnecessary, sure, but it is pretty badass. And it would sure speed up any tank cycling you've got to do in the future.


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## jaidexl (Sep 18, 2006)

This is true, I have a 40br to set up, I can totally avoid any headaches with this army of bacteria on standby.


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## Sharkfood (May 2, 2010)

> The best HOB's are Aquaclears


Using this type of HOB effectively eliminates the issue you referred to.

I'm quite surprized that other manufacturers haven't started emulating this design.


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## fresh.salty (Jul 2, 2010)

Most manufacturers design the filter to sell filter cartridges. Look at Rena's HOB and the newish API canister. Those aren't impossible to DIY, just more difficult than most.


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## DarkCobra (Jun 22, 2004)

You can blast out the gunk in most filter inserts with a high-pressure jet of water. I use a Showerpik. At normal settings it works well for its intended purpose, dental irrigation. At the highest settings, it would flay the gums from your jawbone, but is perfect for pressure cleaning. 

When any foam insert or prefilter gets too clogged for even that, I put it in the washing machine with oxygen bleach and hot water, followed by two complete cycles of hot water alone. Cleans it just like new. Not acceptable for some items, like cartridges that integrate filter floss and carbon, for obvious reasons; but these are thin enough to be easily pressure cleaned anyway.

I've never actually had to throw out any filter insert, short of a single Magnum filter sleeve that just fell apart.

For the Aquaclears, raising the foam media to the highest position will block the overflow holes in the side of the basket, which can otherwise mask that your foam has become clogged. It also makes an AC into a much better CO2 diffuser, as the bubbles get caught underneath the foam and dissolve; rather than bouncing off the foam and rising to the top of the impeller chamber to be wasted.

Also, those plastic "poof" potscrubbers make very good biomedia. A few bucks at a dollar store will buy you all you ever need. You can stuff them into darn near anything.


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## fresh.salty (Jul 2, 2010)

The Rena sleeves fall apart at the seam. Now I use Marineland's filter material and rubber bands as the replacement. The rubber bands start breaking down in about 3 months. lol

Penguin cartridges will last about 2 years for me before they disintegrate.


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