What does a wet/dry filter do?

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maxwellag

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I have been looking at filters, and some of them have wet/dry filters. I was wondering what they do, and what the benefits of them are. Thank you
 
Wet dry filters combine water and air on their surfaces to increase the amount of oxygen for the good bacteria by a very large factor.
They do this in various innovative ways, such as rotating wheels built into a power filter, or multiple-faceted balls piled high in a sump, some above the water line with the water dripping over them into submerged balls...all covered with bacteria.
 
i love how basically every thing about wet dry filters revolves around nitrate factories. it was a study that was released then RETRACTED yet noone looks at that. in a probably maintained system a wet dry filter is the best.
 
with poor maintenance, ALL filter media can become nitrate factories.

Loweing nitrate levels can be achieved with understocking, routine filter and gravel cleaning and water changes.
 
Hang on... My basic understanding of bio-filtration is as follows:

Ammonia -> Nitrites -> Nitrates

In all circumstances... Surely all biological filters are "nitrate factories"? That's the point of them?
 
The Editor said:
Hang on... My basic understanding of bio-filtration is as follows:

Ammonia -> Nitrites -> Nitrates

In all circumstances... Surely all biological filters are "nitrate factories"? That's the point of them?

Massive biomedia capacity is the selling point for me.
 
The Editor said:
Hang on... My basic understanding of bio-filtration is as follows:

Ammonia -> Nitrites -> Nitrates

In all circumstances... Surely all biological filters are "nitrate factories"? That's the point of them?

Not all biological filters are nitrate factories. Mud beds or deep sand beds are just the opposite. The bacteria that consume nitrates are araerobic and do not like to oxygenated, and prefer to live deep in mud or sand beds. That's why many in the aquarium hobby, both freshwater and salt, are adding refugiums to their systems. Other than my sons little 20 gallon freshwater (which has a marineland emperor 400 bio wheel), I have mud beds in all my tanks including freshwater. Much better than wet dry in my opinion, which have always been nitrate factories for me.
 
Not all biological filters are nitrate factories. Mud beds or deep sand beds are just the opposite. The bacteria that consume nitrates are araerobic and do not like to oxygenated, and prefer to live deep in mud or sand beds. That's why many in the aquarium hobby, both freshwater and salt, are adding refugiums to their systems. Other than my sons little 20 gallon freshwater (which has a marineland emperor 400 bio wheel), I have mud beds in all my tanks including freshwater. Much better than wet dry in my opinion, which have always been nitrate factories for me.

Ah ok.. Granted I'd completely forgotten about anaerobic bacteria ;)

But the anaerobic bacteria that live in the deep mud/sand beds still require the presence of Nitrates in the water column for them to digest them into nitrogen. So the Ammonia -> nitrite -> nitrate step must still occur at some point or time in the bio-filtration media?

My main question is how is a "nitrate factory" different to any aerobic biofilter that converts the ammonia to nitrates?
 
The Editor said:
Ah ok.. Granted I'd completely forgotten about anaerobic bacteria ;)

But the anaerobic bacteria that live in the deep mud/sand beds still require the presence of Nitrates in the water column for them to digest them into nitrogen. So the Ammonia -> nitrite -> nitrate step must still occur at some point or time in the bio-filtration media?

My main question is how is a "nitrate factory" different to any aerobic biofilter that converts the ammonia to nitrates?

+1 to this. Old school aquarium keepers believed they could not produce an anaerobic area for fear of releasing toxic gases along with the nitrogen. There are still lots of people who will tell you that upsetting a deep sand bed will release toxins. In old school, you got rid of nitrates with water changes and plants.
 
+1 to this. Old school aquarium keepers believed they could not produce an anaerobic area for fear of releasing toxic gases along with the nitrogen. There are still lots of people who will tell you that upsetting a deep sand bed will release toxins. In old school, you got rid of nitrates with water changes and plants.

What toxic gasses?? I'm guessing an unwanted anaerobic bacteria would be responsible but what do these bad bacteria digest to produce these toxic gasses?

I still don't see how having a massive wet/dry surface area in a sump will produce more nitrates than a regular filter. A certain stock of fish being fed a certain amount of food will produce a certain amount of waste which will be converted in the filter..

Regardless of the potential maximum bioload of the fiilter, surely the quantity of nitrates produced is directly linked to the stocking of the tank and the husbandry of the aquarist.... The best filter in the world can't produce nitrates unless you're feeding it ammonia....
 
now im confused lol...I thought it was good to have a "nitrate factory" its an easy fix, weekly 10% water changes....or so I thought..That this is the "problem" you wanted, not high ammonia or nitrites....oh boy
 
I've been following this as I just acquired a huge brand new bio ball using wet dry for my upcoming 90g FOWLR.

I understand the process or so I thought.....This thread was clarifying things but now I'm back to confused. LOL

The bioballs are supposed to have nitrate on them correct? The nitrate that resides there won't build up too too much if you do water changes though right? Or do youhave to clean out the bio balls every once in a while? There would still be enough converting bacteria left in the tank wouldnt there be?

Thanks. as you can see I'm confused. LOL
 
As I understood it all biomedia was just material with a high surface area to volume ratio, since the good bacteria anchor themselves on surfaces the more surface you can pack into the filter the better...

I wouldn't have thought there would be sort of build up of nitrates within the bioballs (or any other media) so long as they aren't sat in static water, even then diffusion will try and naturally equalise the concentration of nitrates throughout the water column. I guess it depends how freely water can flow through them...

Maintenance of them would depend on your setup.. If you're pre-filtering the water to remove suspended particles etc.. then maintenance would be pretty easy.. Just half of them and give them a rinse in aquarium water every few months.....

Though I must say I have exactly zero hands on experience with bioballs or wet/dry filters :p I'm just asking the questions!
 
The reason why some people say that wet/dry filters are nitrate factories is because food and waste particles can get trapped inside the filter media (read: bio balls etc) if there is no mechanical filter in front of the wet/dry part. This in turn can cause nitrate spikes as the material in the filter rots and the BB converts the rotted waste into nitrates.

Same thing can happen on your regular HOB filter if there is no mechanical filter (ie: spounge etc).

It really comes down to how clean your tank is kept and if you have mechanical filtration in front of the wet/dry. All filters produce nitrates. That's why you have to do water changes. It's the possible nitrate spikes in a wet/dry system that people are scared of, but if you have mechanical filtration and change the spounge or what ever on a timely manor you will not have any issues.
 
So in short, a nitrate factory is the result of poor maintenance?

How about wet/dry running in combination with deep sand/mud beds? Surely then you can reap the benefits of both.. Large biocapability of the wet/dry set up combined with the nitrate reducing bed...

Even if the bed isn't big enough to deal with the nitrate load of the entire tank it would allow you to make smaller or less frequent water changes right?
 
Yes poor mantenance will cause nitrate spikes on any filter systems, wet/dry included....it's really important to be on top of your mechanical filtration when using a wet/dry filter.

I don't see why you couldn't have a mud bed and a wet/dry you would just need a sump for your wet/dry and a refugium (spelling?) for your mud bed. Just means that you would need a bit more space under your tank to store all that.

More filtration is never a bad idea and usually if you have a filter system that is larger than what the tank actually requires then yes you can do less water changes. One of the other advantages of a sump/refugium (again spelling) is that it adds water volume to your aquarium system so you have a much larger buffer for nitrates etc that you would with out them. An example would be a 29 gallon with a 10 gallon sump. Instead of only having 29 gallons of water in the system you actually have 39 gallons making it much easier to maintain proper water.
 
I would think you are correct. FWIW I run a reef with a wet/dry and bioballs. I do not consider myself an expert by any means. My sand bed is only about 1" to 2" deep. I'll see if I can post some pictures of my sump in a couple of days when I get back home. (Pictures here: Aquarium Advice - Aquarium Forum Community - Rutrag's Album: 37 Gallon Beginner Reef)

One alternative I have seen (and cannot speak to its effectiveness) is to run chamber with some kind of media with low waterflow off the sump. The theory is that the water becomes anaerobic and the media provides a surface for the anaerobic bacteria. Others use live rock where the theory is that water permeates to the middle of the rock at a slow rate, and it's anaerobic by the time it reaches the core.
 
So I have just skimmed over this and I thought I would throw in my 2 cents. A wet dry filter is old news and is hardly used today. The best and I mean best filtration system somebody can run today is a combo of allot of diff techniques. This is what I have cone up with. Start off with a Pre filter such as a filter sock, next go into a algae turf scrubber, from there into a protein skimmer, and last but not least a fuge filled with a dsb and a variety of macro algae and live rock rubble. If you are looking at filtration systems this is prob by far the most natural and best. Also as a side note if you have room you can add mangrove into the fuge for even more filtration.
 
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