5 Benefits of Wet/Dry Filter Systems for Your Aquarium + How They Work

Wet/Dry Filters: The Greatest Thing Since Sliced Bread for Your Tank!

You may have not heard of this kind of filter before.

That’s okay, you’re going to get in on the secret now. πŸ˜‰

A wet/dry filter (also called a trickle “filter” or “shower filter”) is amazing for fish… and for you.

1. More efficient than conventional filters

We’re talking anywhere from 2 to 10 times more efficient.

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When the filter media is exposed to air and water at the same time instead of submerged, the bacteria does a WAY BETTER JOB converting ammonia to nitrate.

More efficient conversion = a healthier tank.

The water that returns to the tank is also extremely well-oxygenated.

Because they are so efficient, when paired with the right kind of filter media, many people actually are able to get away with stocking their aquariums more heavily than normal without water quality problems.

2. Lower current

The bacteria in wet/dry filters work off of oxygen in the air, not the water (unlike with HOB filters). That means you don’t need those high water turnover rates that stress out fish with more exaggerated fins and rounder bodies.

Low turnover rates means less current.

This is perfect for slower-moving fish such as goldfish.

3. Cut down Your Tank Maintenance

Do you ever get tired of doing so many water changes?

It might seem too good to be true to be doing a water change maybe… once a month rather than once a week.

Well, now you can.

When using this kind of specialized filter media, such a filtration setup has the incredible ability to actually reduce nitrates – a feat no hang-on-back-filter has ever been able to accomplish!

As you may know, nitrates are one of the biggest reasons frequent water changes are necessary for a tank.


80% of aquarium owners will QUIT after 2 years.


They don’t have the time or motivation to be putting in hours of tank maintenance every month.

But with the right kind of setup, you can make fishkeeping way less work for yourself – spending more time on things you enjoy doing instead of hauling buckets.

Are you excited yet?!

Yes, the fish will probably require some minimal water changes, but lower nitrates stimulate spawning and growth.

The monthly water change can consist of vacuuming debris that accumulate on the bottom of the tank.

4. You Can Grow Plants in Them

This is crazy:

The round filter media pieces (more on those later) that make a perfect home for bacteria in this setup are the #1 preferred media for use in something called…

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If you aren’t familiar with the word, it basically means using fish waste to feed plants by pumping water to their roots.

Many kinds of plants can grow in the top level, adding more filtration and aesthetic value.

What, even more filtration? You bet.

Garden vegetables are an extremely popular in aquaponic systems because they grow fantastic on fish waste, helping to break it down and use it for nutrients.

I mean, you are literally using your goldfish to make your own food! πŸ˜€


Well, maybe not.

The concept has been around a long time, we’ve only recently used our technology to do it.

And if you are most concerned with how your tank looks overall, you can even grow trailing plants like devil’s ivy over the side to conceal the setup.

You’ll want to use the filter mediaΒ in the top level and provide a light sourceΒ such as this grow light.

This kind of setup is ideal for them because their roots are constantly receiving water while there is still ample oxygen around their roots, preventing them from “drowning.”

5. Better than Sponge Filters

Sponge filters for goldfish have become pretty popular, and I’ve advocated using them myself. In fact, with regular cleaning and large frequent water changes they can be a good thing.

Here’s the drawbacks of sponge filters:

Because the mechanical filtration is not separated from the biological filtration (it all occurs on the same surface), the sponge gets covered in debris that choke out the beneficial bacteria and stop them from working well.

The solution?

Frequent cleaning.

They also can’t help in reducing nitrates. So you have to do water changes regularly to keep those down and keep the debris out.

Especially for heavier waste producing fish such as goldfish, they may not be a very powerful solution.

Just some things I’ve found after my years of use with them. You can still use a sponge filter in addition to a wet/dry filter for added aeration/water clarifying if you keep it clean, but it isn’t always necessary.

I got this style of wet/dry filter and absolutely love it. Super awesome quality, the boxes are surprisingly weighty and not cheap flimsy plastic. Setting it up was very intuitive and didn’t take that long at all.

It’s worth every penny when you realize how much it saves you on the water bill (not to mention your time!).

To use it you will need a submersible pump.

The size you get will depend on the size of the tank; see the product for recommendations.

It doesn’t come with the media you need to grow the colony of beneficial bacteria, but more on that and where to find it below.

How to Set Up a Wet/Dry Filter System

Setting up your trickle filter is like making a sandwich.

There’s a lot whole lot of good ways to do it. πŸ™‚

I’ll share my preferred method below, which is super simple.

In the highest level of boxes, I first put down a single layer of nitrate reducing filter media.

Then on top of that I put a thin clarifying pad to help with straining out particles.

Only some specific kinds of filter media allows for nitrate reduction…

… But lucky for you, they aren’t too hard to find πŸ™‚

Those plastic bio balls won’t ever clog up, but they turn into nitrate-producing (NOT reducing) factories so I don’t recommend them.

So I prefer something else:

Seachem Matrix or FilterPlus media pieces actually help eliminate nitrates.

Another plus is that they are lightweight. You can use a ton of it and it doesn’t add much weight at all.

On the surface, you have a home for aerobic bacteria that converts ammonia into nitrate.

Then deep in the core, you have a dark, low water flow and low oxygen area perfect for the good anaerobic bacteria that break down nitrates.

I try to give the pieces a little space in between so that debris doesn’t get trapped there – that’s why I use the clarifying pad. This pad is optional but can make collecting waste easier.


There isn’t any point in collecting debris if you are just going to leave it in there to pollute the water.

That’s why I advise rinsing the pads weekly if you choose to use them.

Then I literally just put more layers of filter media in the lower levels of the boxes.

That’s it and that’s all I do. Easy as pie, right?

Other Things You Can Put In Your Wet/Dry Filter

If you have trouble with your pH you can put alkalinity/acidity adjusting products there too.

For goldfish, adding crushed coral or oyster shells is a good idea as goldfish prefer harder water.

If chemical filtration is desired, putting the carbon at the bottom is a good way to go.

You can use sacks of carbon sticks, or a carbon infused pad.

However, I’m wary of using carbon based on its proven direct link to disease in some fish.

Instead, many aquarists are having success using Seachem Purigen to help reduce organic matter and keep the water crystal clear.

Unlike carbon, Purigen actually changes colors so you know when it’s exhausted.

A large sponge distributed through the middle boxes can help to trap solids and provides additional surface for bacteria to grow on.

Personally I don’t like these because they are difficult to clean. This will need to be swished out frequently in a bucket of tank water to prevent it from clogging up and getting nasty.

What do You Think?

Have you ever tried using this system for your aquarium, and if so what were your results?

Are you potentially considering switching to this kind of filtration?

I look forward to reading your feedback in the comments below.

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  1. Joseph E LaBranch January 17, 2018 at 4:23 am - Reply

    I’m all convinced of the necessity of sump filters especially in bigger aquariums, back in the day all my 100 to 240 gallons were run with sumps generally 40 to 60 gallon breeders, I also would 2 or 3 run 500s ( now 110s) just cause I did on these aquariums, didn’t really mess with canisters. With filtration more is better and the hobs moved surface water like nothing else in summer that can be a big plus in California, plus I’m convinced that current in a goldfish aquarium builds necessary musculature in the fish, just like a koi pond needs to be 36+ inches deep to fully develop musculature in them.

    Rating: 5
    • Joseph E LaBranch January 19, 2018 at 3:40 am - Reply

      I need to correct one thing, I would run two or three 500 (now 110) filters in these aquariums. If you are trying to use a sump as a way to get away from water changes, I don’t think that’s reality, however keeping more water better quality, yes, by all means however all the aquariums were graveled and planted. Believe this is good for my fish as well. Never did Hydroponic a sump filter, I personally think it is a great idea, might try it setting up a new aquarium 75 gallon for a couple of lemon cap Orandas and I plan on using a 29 gallon sump.

      Rating: 5
      • Pure Goldfish
        Pure Goldfish January 22, 2018 at 12:35 am - Reply

        Thanks for sharing your experience, Joseph! I’m trying hydroponics right now with pothos plants.

    • Pure Goldfish
      Pure Goldfish January 22, 2018 at 12:52 am - Reply

      Never thought about the musculature aspect before. Very interesting.

  2. Joseph Karthic May 5, 2018 at 8:04 am - Reply

    Could you please explain a bit more how the nitrates are reduced in this filter setup? you said

    “Then deep in the core, you have a dark, low water flow and low oxygen area perfect for the good anaerobic bacteria that break down nitrates.”

    Where is this happening? Also does the nitrates are reduced by only using hydroton clay or can we use normal bio media like Matrix/ceramic rings etc/.???

    Please help

    Rating: 4.5
    • Pure Goldfish
      Pure Goldfish May 6, 2018 at 7:13 pm - Reply

      I’ll do my best πŸ™‚ Within the center of each piece of filter media it is dark and low in oxygen. Nitrates are reduced with the use of certain media, including Matrix/FilterPlus. I actually wrote a more in-depth article about nitrate reducing filter media which you may like to check out.

  3. Steve June 4, 2018 at 5:40 pm - Reply

    It would be handy if I could actually find a trickle filter for my aquarium, not one of the dealers in this area keep them.

    Rating: 5
    • Pure Goldfish
      Pure Goldfish June 9, 2018 at 5:31 pm - Reply

      Hey Steve, maybe you can try here πŸ™‚

  4. richmaynardjr July 28, 2018 at 2:20 pm - Reply

    Our 210G has been real happy with its current setup of:
    A combined AE over the Aquarium filter
    (Five level, of the 6wide by 3high, & 4wide by 3)
    Marineland 360 canister
    Cobalt 50G canister
    One large sponge filter

    Rating: 5
    • Pure Goldfish
      Pure Goldfish July 29, 2018 at 1:26 am - Reply

      Everyone has to find what works for them, glad you’ve found something that works for you πŸ™‚

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