I recently set up a 29-gallon aquarium on a rack below Otis, the F8 puffer. The 29 contains a modest number of Endler's livebearers, a tiny black Moor goldfish (about 2-2.5" inches long) and some ramshorn snails. The rack is located in a hallway entrance to my kitchen, next to the powder room. This wall is a great location because the tanks are easily viewed from several perspectives, and both tanks are only 12" wide (front to back) so they don't stick out into the room very much, thus not blocking traffic in any way. However, once you start scooting the double tank stand away from the wall to accommodate an HOB filter you lose the streamlined look and it looks cluttered by the equipment, plus it becomes more intrusive into the pathway in and out of the kitchen. Otis has a small Eheim canister filter which sits in a tall, narrow flower pot on the floor next to the tank, and to the casual glance this pot looks like a trashcan or something, and you don't notice the filter. This also enables the stand to be placed close to the wall.
When I set up the 29-gal tank on the rack below Otis' tank I tried to utilize another very small canister filter next to the tanks by placing the flower pot on a plant stand and putting the second filter on the floor beneath Otis' canister filter. This worked, but did not look right, and though it did not intrude into the room very much, you noticed it and you had to avoid it when coming in and out of the powder room. I was not happy with this arrangement, and I knew I could do better. I put an AquaClear HOB on the 29 and did not have to move the stand very far off the wall to accommodate it, and I was content with it. AC filters are not solid black but an opaque grey and it was not very noticeable.
Unfortunately, there was a tiny and nearly invisible crack in the housing of the filter, and a small leak was evident in no time at all. I think I can repair this with epoxy, but it had to go for now. I had a Penguin 300 or something similar, the type with two filter pads on each side of the intake. This is too much filtration for this tank - the flow is too high - and this filter is old and makes a horrible grinding noise. I left the tank unfiltered most of the time, which was okay considering the low bioload. I dug through all my aquarium equipment (I have accumulated quite a lot over the years!) and could not find a filter that I was happy with, so I ordered an inexpensive small Aqueon HOB filter. I have one on my 10-gal snail tank and I'm happy with it.
In the meantime, waiting for the filter to arrive, I came across the video tutorial on making your own internal filter using a resin aquarium/terrarium decoration. Pond Guru used a fake rock with a hole in the bottom, but I realized I had a fake driftwood resin ornament. This thing is meant to stand up, vertically oriented, and is quite tall, which is good, because the 29-gallon aquarium is 30" tall and I could use this to hide the heater in the back corner.
What you do is drill small holes in the top of the ornament, or what will be the "top," depending on how you have it oriented in your tank. Pond Guru installed suction cups so he could attach it to the back glass, but I planned on parking this thing in a "standing" position in the corner, so no suction cups required for my application. The ornament is relatively heavy and won't float up. Since the top of the wood design is quite irregular, with jagged peaks and valleys like a piece of wood, I drilled holes in varying locations at the top. I drilled a total of 6 or 7 holes. This is the "outflow" of the filter.
There is a good-sized hole in the bottom of the ornament, which will be the "intake." I drilled a hole into the back of the ornament to accommodate an airline tubing, larger than the holes drilled in the top, exactly the same diameter as airline tubing, and placed this hole about 4" up from the bottom hole. I turned it upside down and poured in Eheim Substrat, using a mixture of the gravel type and the small "ball" type, filling it to where the airline tubing hole was drilled (holding it upside down). I fed the airline tubing through the hole and on the inside I attached an air stone, the kind that is about the size of a large olive, to diffuse the air inside the filter. Pond Guru did not do this, but used a T connector to hold the airline tubing inside the ornament, so air would come out each arm of the T inside the ornament. I don't know if it makes any difference at all, but for some reason I felt like I ought to diffuse the air. After that I gathered up some foam inserts of varying coarseness and shoved them into the hole in the bottom, holding the coarse media inside the ornament and allowing water to flow up through everything once it is in place in the tank. I used the coarsest foam at the bottom (coarse AquaClear sponges) and got finer as I went up, with the finest blue filter pad, like what is used for HOB cartridges.
Here's a pic of things before I put it in, and I ought to have taken pics of the entire build, but it was done in under 30 minutes and I forgot to get pics.
See the tank in the background close to the floor? That's the tank where I put the filter. I was going through all my aquarium supplies and found the castle ornament, which has multicolored LED lights that fade in and out, and for old time's sake I put it in there, but removed it after I put in this filter, since it really is a bit corny and looked out of place.
The only problem, which is somewhat evident when you look at this pic, is that the fake driftwood is a bit taller than 30"!! So, this means that once installed in the back corner the very top of the ornament is out of the water. There is a hole drilled there, so there is some gurgling/bubbling sounds that are slightly annoying, but can't be helped, lol. I ought to have placed the ornament in the tank prior to using it for this tank, but it will do the job. I used a Rena 400 air pump, since the tank is relatively deep and the small air pumps I have couldn't really get the air all the way down to the bottom. This pump is virtually silent.
Here's how it looks in the tank:
So here it is, located in the back right corner behind the Java. You'd never know there was a filter on this tank at all. The water is a bit cloudy from me shoving things around, but that soon settled. I think it will take quite a while for the media to support a thriving colony of bacteria, but in the meantime I'll continue my water changes and not add any livestock (if I can help it...) other than the Endler's babies. I have places for excess Endler's to go, at any rate.
I know I already credited Richard (Pond Guru), of Tyne Valley Aquatics, an aquatics/pond/landscaping business in the UK, but I want to thank him again for this great hack for those resin ornaments we've all used or are using. There are some very clever ideas to be found on his YouTube channel, so check it out. My daughters thought I was the most brilliant mom ever when I whipped out my drill and my filter media and put this thing together in no time flat, but I had to admit that it wasn't my idea, but something I really wanted to try.
For many years I have been an advocate of robust filtration, usually overfiltering my tanks, out of an abundance of caution that I'd underfilter and create dead spots in the aquarium. If some filtration is good, then more must be better, right? Well, the water rushing past the media at breakneck speed does not really give it a chance to accumulate bacteria in an efficient way, which is, ultimately, what we're looking to do. I do, of course, want to use mechanical filtration to "polish" the water and remove particles, but the primary job of the filter, to my mind, is to support bacteria that remove ammonia and nitrite.
A slow filter such as this could be key, in low bioload applications, to a healthy tank, and since it is such a departure from my normal practices I'm looking forward to seeing the results.
I will keep you posted!
