NEW w/ POLL canister vs. wet/dry

[HarleyK]

Howdy,

It seems to be popular opinion that a wet/dry filter is more suitable for large MONSTER tanks than a canister. However, I have yet to see any hard data supporting that notion. Obviously, large canisters combined with modern biomedia have come a long way and do the job just fine. Besides possible DIY savings, what are the benefits of wet/drys? I don't get it. You have to drill your tank or construct some obscure pumbing, you have uncontained water running outside your tank. These two factors alone make me wonder what the true appeal of a wet/dry is besides $.

Is there any evidence that a wet/dry is a better filtration?

Please do not post dubious websites that claim one or the other in order to make a sale. I want to hear about your own experience or want to get links to hard data with one-on-one comparison of equivalent filtration set-ups.

So far, I think it's a mere user preference . ... but it often gets posted here as the indisputable truth.

Let the discussion begin, but stick to the facts
Thanks for your input,
HarleyK - The Canister Man

 

[Oddball]

That is an outstanding subject to research. Let us know what you find out.

 

[rallysman]

These are the reasons I prefer wet/dry over canisters:
Easier to clean (way easier) You can also look at the media to see how "dirty" it is.
More versatile, you can hide all sorts of stuff in a sump, including fisht that need to be isolated.
Larger capacity of bio media (and whatever other media you want)
easier to maintain, all you have to worry about is the pump, and you can have 2 pumps for redundancy.
Cost!

I'm sure there are more reasons that I'm not thinking of, but I've never had good luck with a canister. I've never tried an eheim or a top of the line canister, but my cheap DIY sump has been flawless and easy to maintain/understand.

 

[rumblesushi]

Harley, as long as you have say - at least 2 decent canisters (eheims) for something 150 or above, and good biomedia like ehfisubstrat then in my experience they do just as good a job.

I agree with you completely, I can't be bothered with all the plumping, and drilling for a wet/dry, when a few canisters do the job fine. It's neater and easier, and I like to be able to move filters to new tanks, not so easy with a sump.

I am also dubious, even with the added oxygen, just how much low surface area bioballs could have more bacteria than a large canister full of ehfisubstrat.

I also like to have 2 or 3 filters on a large tank, in case one fails.

 

[Oddball]

I use both types of filters. I prefer Wet/Dry setups because I can filter multiple tanks on one pump (with UV for isolation purposes). I can also inject a current of air into the bio-chamber to improve the gas exchange of the bio-media.

 

[StevePerry]

Water dripping through the drip pan in a wet/dry also provides copious amount of gas exchange. Wet/dry's also give you a plave to hide heaters, sterilizers, skimmers and such.

 

[redtailfool]

I use both . I prefer the wet dry more for the for the reasons rallysman stated above and that a wet dry utilizes a sump.. basically a small tank connected to a big tank. This is good for isolating some fish from the main tank and just for the fact that you can have more water than your tank can hold. More water is always a good thing right?

Wet dry filters doesnt have to be plumbed Joe. You can always use a overflow that hangs on the back of your tank and a return line can be any hose that would lead back the filtered water to the tank.

 

[rumblesushi]

actually wes that's how I used it before A bought wet/dry with overflow box.

But for instance, they don't sell them in this country, and I needed to upgrade filtration as I smashed a canister.

If I made my own I would have had to drain and drill the tank, then build and plum the sump.

Much easier to buy a couple of eheims

I agree there are certainly some positive aspects. Hiding heaters etc, good oxygen exchange, but I didn't think the sump with bioballs/sponges did any better than a couple of eheims as far as mechanical and bio filtration.

Also none of the crap on the ground gets picked up, as the overflow chamber is at the top of the tank.

 

[HugeGhost]

The resaons wet dry is so awesome is the air. When the bacteria can get air it grows alot faster. Can anyone tell us how much better it is having the media contact air.

 

[HarleyK]

Howdy,

Thanks for all the great input already. Let me address a few of the aspects you mentioned in order to present the canister man's view

• I see the advantage of hiding equipment such as heaters, but Eheim is coming out with a big thermofilter soon.
• when it comes to isolating fish, wouldn't it be better in a tank that is not connected to the main water circulation?
• Oddball has a good point in that one sump can serve several tanks.
• I have yet to experience a water leak with my Eheims (25 years, knock on wood), as compared to sump overflows (I think rallysman's was the latest report). I have to admit that the FX5 also caused a water leak in Oddball's system and other people's tanks. But then, these are teething problems of a new design and I have yet to hear about a similar experience with Eheims.
• a wet/dry aerates in the chamber, a canister spray bar can be just as effective in the tank. On the other hand, the spray bar can be installed below the water surface to prevent CO2 from escaping in planted tanks. That is not an option with a wet/dry.
• as rumble said, a canister removes sediments, while the overflow only catches dissolved or suspended matter
• rally can see when his wet/dry gets dirty, I can tell my canister's level of dirt by the flow rate
• while direct contact with air boosts bacterial activity, canister's biomedia have 1000x more surface area for bacteria than bioballs and partly allow anaerobic denitrification.

All in all, it still seems a lot like personal preference and the power of the $$$, which I absolutely understand.

The key question is:
Has anyone ever switched from a big canister to a wet/dry or vice versa and noticed significant differences in filtration quality?

HarleyK