I run two filters on the majority of my tanks. Most of them are HOB+sponge. One is HOB+canister. All of them have prefilter sponges tho so I'm essentially running sponges on everything.
The air driven sponge filters are a very nice backup since air pumps use up very little energy for the number of filters they can power. So I put the air pump on a 400VA(255W) UPS battery backup and when I have power outages it will continue to run for hours even on the cheapest of UPS. I use a Whisper Air 100 which I recall on paper used just 4.8W. I'm only covering for the pretty common 1-2 hour outtages we get around here, so I just picked a fairly cheap option for UPS.
The flow rate will vary with how much air you put through the sponge and the diameter of the airlift tube.
Yes that's fine It would provide some extra biological filtration and oxygen in the water. Go bigger for more bio filtration, but as a secondary thing, it is just fine The rate will depend on your air pump, which just has to break the water surface with bubbles.I've add several plants with the hope of created a moderate to heavily planted tank...
What do you think of this as a backup for my 65? I have no idea what the flow rate is on something like this though...
Using a sponge filter in a tank I'd always good thing to have. My tanks all have sponge filters to supplement the primary filter.
Are you in US or Canada ? I ask because some items are not available in Canada, so I don't want to reference a product that is not available to you
I too run sponge filters along with my HOB’s. I had a situation just this summer where I was camping and had a sitter caring for my pets. She called to say that my Aqua Clear was making a funny noise. I was able to tell her just to unplug it until I got home since I had the sponge filter too. I like having back ups in the tanks.Sponge filters serve more than one purpose. I run 2 dual sponge filters along with 2 HOB filters in my 55 gallon tank. They add extra surface for bacteria and can be used to start or even instantly cycle another tank.