Upgrading Tank Sizes

BobbyBray · Oct 6, 2009

The Story:
So I'm getting married at the end of this month, and both my fiance and I have 29 gallon tanks. Rather than have two in our new apt, I decided to just get one large tank and sell the two smaller ones. This week I found a good deal on a 55 (US) gallon (208~ish liter) tank. It seemed like a pretty good setup, comes with the tank of course, stand, hood, lights and some other misc stuff. But it will also have a Eheim Pro II 2126 filter, which seems very slick, though I've never really used it.

The kid I'm buying it all from had 5 or 6 piranhas in the tank, but I'll just be stocking fairly simple community fish. I assume the filtration will be more than sufficient since tetras and community fish are usually much cleaner than their meat eating cousins.

The Questions:
Since the tank will be 'over' filtered, does that mean I could 'over' stock it with more fish than would normally be advised?

The only draw back I see to this Eheim canister filter, is the water flow back into the tank isn't falling into the water, and thus not adding any extra oxygen into the system. Could this pose a problem? Should I get one of those bubble screen thingies to help oxygenate the water?

We'll probably stock the tank with your standard community fish, neons, tetras, cories, hatchets, rainbowfish and such. But my fiance wants a nice centerpiece fish that would (preferably) not eat the other smaller fish. Maybe something that gets to be 6 inches or even larger.

Thanks!

drobbyb · Oct 6, 2009

Over filtering a tank will allow you to overstock some. People who keep african cichlids do it all the time, but usually they have about 10x turnover rate/hour. The filter you mentioned only does 4.5x turnover (250 GPH/55 = 4.5), so you woud need even more filtration to do that. I don't understand why the filter is rated for a 100 gallon tank with such a low flow rate.
"Professional II Model 2126 For use in tanks up to 100 gallons, 250 gph flow rate at 25 watts, 2 media containers hold up to 4.9 liters (1.29 gallons) of media. Also includes 180-watt integrated heater (for freshwater only). ."

As far as the aeration goes, a simple airstone tucked away in a back corner would solve that problem.

snowflake311 · Oct 6, 2009

The classic ehime canister has a slower flow rate so that the water spends more time in the filter where the waste is converted. So it is more for better bio filtering. If water is just rushing over the media it does not get to come in contacted wit has much of the media as it should.

I have this filter for my 55 gal it is great. You can adjust the spary bar so that it hits right above the water to help with adding o2. You can put the spary bar any place you want. I have mine so the water flows from one end to the other end of the tank moving water all around the tank with little to no dead spots.

BobbyBray · Oct 6, 2009

hmmmm, I never thought about the turnover rate being the big factor, but thats a good point. And it does seem low for a filter of that size, my current marineland bio wheel does 200 GPH.

I'm still interested to hear from other people who have used these external filters, and if they have trouble with aeration or not. Though like Drobbyb mentioned, and airstone is a simple enough fix to that.

Ahhh, posted right after you Snowflake, thanks for the input. Thats good to hear that its easy to adjust the amount of o2 entering the water, thanks.

MrPurplePickle · Oct 7, 2009

I've got a ProII 2026 on my 240ltr tank.
As Snowflake said, no problem with aeration just adjust the spray bar.

I've found the overall flow is possibly a little inadequate, so have a small powerhead as well.

Hope that helps.
Cheers

BobbyBray · Oct 7, 2009

The tank setup will also come with an Eheim powerhead as well. I didn't think it would make that big of a difference, so I didn't even mention it before. Does the powerhead help to just circulate the water around and help the whole filtration process? Or does a powerhead help with something more that I don't understand.

I don't know for sure what kind of powerhead comes with the whole setup, again I didn't even think it was going to make a huge difference, so I was wondering if I even needed to use it or not. I wasn't sure if a powerhead would create extra turbulence that the smaller fishies wouldn't like. At any rate it was something like this: Eheim Aquaball Powerhead

I should have the whole setup in my hands, and hopefully running in a week or two. I'll have to take some photos and post them here.

MrPurplePickle · Oct 7, 2009

I use it to just help with flow, my tank is reasonably planted and i had a couple of dead spots.

My Angels aren't big on too much flow, a bit of trial and error with positioning and everyone was happy.