What to Look for in a Planted Aquarium Filter?
As I am always saying, our planted aquarium is an enclosed ecosystem that is very less in terms of water volume compared to the faunas’ natural habitat. The water, minerals, and nutrients are constantly being replenished in rivers, springs or streams, etc. (lotic – running water systems). Even lakes, ponds, and swamps known as lentic systems (still bodies of water) are being replenished by precipitation (small and numerous streams replenish some lakes and even have ways to drain themselves). Whereas in our tanks, we have to make do with regular weekly water changes. In this article, we will discuss what to look for in a planted aquarium filter.
Table of Contents
What to consider when looking for the right filter?
Your Tank Size/Volume
The Types of Filtration it can Provide
What to consider when looking for the right filter?
Having plants in an aquarium is not a justification for having no filtration. The plants cannot do it alone, even in the most natural of systems.
Less water volume means the water gets polluted faster, and your water parameters can go out of whack in an instant, most especially if your planted aquarium is not cycled yet. And this is augmented if you have a smaller tank (nano tanks). So choosing your filter is very critical. Buying a filtration system for your planted aquarium is not just about buying a filter you had been eyeing because it looks great or looks big enough or having a lot of features that you may or may not be able to incorporate in your planted tank, etc. It is not about buying a filter just for the sake of having a filter and be done with it.
85 Gallons Main Planted Tank Using a 25 Gallons Sump Total 110 Gallons Running – Philippines
It is about providing a conducive enclosed ecosystem for our faunas and plants, and choosing the right filter is the utmost part of that. Do not compromise with your filter. Deciding on the right filter, filter media, and the dedication to keeping up with your maintenance is essential to a successful planted aquarium. To determine the right filter for you, here are the considerations that you need to take:
Your Tank Size/Volume
When hunting for the right filter for your planted aquarium, you must know the volume of your tank in gallons or liters. It is unforgivable for a hobbyist not to know that. Since we emphasized previously the importance of determining first the ideal location of your planted aquarium at your home and then determining the dimensions of the tank that will fit your ideal location and the chosen stand, the store where you will buy your tank can guide you what tank volumes can fit from their selections. The ideal location for your planted aquarium is thoroughly discussed here.
For example, if you have a 20 gallons tank, you should aim for x10 gallons per hour turnover rate (gph). The turnover rate of a filter is how many times your filter can turn over the whole water volume of your tank in one hour. This means, for our example above, you should look for a 200 gph filter. Personally, I always prefer an oversized filter that can house a lot of media with a minimum of x10 tank volume turnover rate. Another example is, I have a standard 35 gallons planted aquarium, so I would choose a minimum of 350 gallons per hour (gph) canister filter like the Sun Sun 303b that I am currently using (rated as 370 gph). The manufacturer rated the canister up to 100 gallons tank.
This was why I got away with unintentional overstocking of fish (my Platies bred profusely started only with 3, and they blew into 40 +). My oversized canister kept up with all the wastes produced at that time frame.
An oversized filter (any x10 gph turn over rate filter based on your tank volume) will work much efficient, and they will be able to take unexpected/emergencies like Ammonia spikes (e.g., dead fish) without the tank’s water parameters even noticing it, plus my tank was heavily planted from the start. But we know a x10 turnover rate filter is not practical in some situations or not feasible for everyone.
My 35 Gallons Heavily Planted Tank Using a x10 gph Canister Filter
So we will recommend at least x5 to x10 turnover rate. A x10 turnover rate filter may be too strong of a current for small tanks (10 gallons and below). Or you can look for a variable flow filter, or you can DIY your way to reduce that flow if you are handy. For example, I know a fellow hobbyist who DIYed his Canister filter to use in a 10 gallons fishbowl.
Other Nuances of my Heavily Planted 35 Gallons Using a x10 gph Canister Filter
You can position the outtake a few inches underwater and then point it upwards the water surface so that the bulk of the water pressure/flow is near the water surface and not towards the bottom where your plants can be uprooted, or your faunas fighting the strong current, resulting to stress. This will also create the needed water surface agitation, aerating your water. And remember, the turnover rate/flow will decrease a bit once you stuffed your filter with different kinds of media.
The turnover rate spec of a filter is clearly listed in every manufacturer’s description of their product. This should be the first specification you should look for when finding the right filter for you. If you know that you want, for example, a 200 gph filter and the manufacturer’s listed their filter in liters per hour (lph), you can convert gph to lph by multiplying it to 3.785. Vice versa, you need to divide lph to 3.785 to get gph. This also applies when we are talking about converting gallons to liters or liters to gallons.
As a rough guide, if you have nano to small tanks (2.5 gallons to bordering 15 gallons), you can try to look for Hang-on-back or internal filters (those that have built-in pumps) that have at least x6 to x10 turnover rate (because x10 turnover rates might be too strong a flow for your tank or try to look for a HOB or internal filter feature that has adjustable rate).
Since a HOB or internal filter cannot be practically installed in a circular tank, I know a fellow hobbyist that experimented with a canister filter in his 11 gallons fishbowl tank. He found a way to adjust the flow and DIYed the tubings.
If you have small to medium tanks (bordering 15 gallons to bordering 30 gallons), you want to start looking for a canister filter with at least x10 turnover rate. You have more room in your tank now that can accommodate higher turnover rates/flow. And there are a lot of ways to adjust that flow if x10 is still too strong. Plus, stuffing a canister filter with all your media will slightly decrease the turnover rate and will continually decrease once it becomes dirty until you clean it.
Nature Style 11 Gallons Bowl Using A Canister Filter Aquascaped by Terence Guillermo Philippines
You can also notice above that the higher volume your tank is, or once you approach 15 gallons and above, the more choices you have. For example, if you have 15 gallons, you can look for a single HOB or a single internal filter, or you can start venturing with a canister filter. 2 HOBs or 2 internal filters are also a possibility (x10 gph combined). I also know many hobbyists who tried/experimented with a sump filter with higher volume than their main tank and succeeded.
Once you progress with tanks higher than 30 gallons to bordering 100 gallons, you can still try a single more powerful canister filter or two less powerful canister filters. You can also start venturing with trickle filters, sump filters, or fluidized bed filters (DIY or customized). It is up to you, and it depends on your preferences. You can also try a single canister filter in combination with a HOB filter or an internal filter.
Then once you approach 100 gallons and higher tanks, you can still use two powerful canister filters (x10 gph combined on opposite sides for uniform distribution of water flow and nutrients) or naturally progress using a static media sump filter, or a trickle filter, or a sump with a fluidized bed biological stage.
As much as possible, avoid sponge filters or corner filters driven by an air pump as your main filtration. Unless they are used as supplementary, they have meager turnover rates and not effective at all in terms of mechanical and biological filtration, plus they take up precious space.
It’s a rough guide, but I know we hobbyists love to experiment, and there is no stopping us from doing that. It is good for your planted aquarium and all the livestock in it. It is good for the hobby too by sharing our experiences.
Using Internal Filters Aquascaped by Martin Ladioray Philippines
The Types of Filtration it can Provide
A planted aquarium filter should be able to provide effective mechanical and biological filtration. That’s all it needs. There are situations where you can use chemical filtration media, but in a completely cycled and stable tank, you don’t need it. Remember, plants act as biological and chemical filtration too. They are alive (biological) and can use excess nutrients and minerals in your water column. They can deprive the algae of those nutrients and minerals, to some extent, so algae cannot infest your tank.
The types of filtration are thoroughly discussed here.
Ammonium, Nitrite, and Nitrates are ions (they are technically chemical compounds – H2O is a chemical compound too!) and can be used by plants to make their food. The byproduct is oxygen for your faunas and beneficial bacteria’s nitrification activities, and you are rewarded with lush growth. As opposed to chemical filtration media, they just adsorb those chemicals/ions on their surfaces. When they reach their capacity, you have to buy again or recondition them, which means you need a spare, or they may leach a portion of those chemicals/ions they adsorbed back into the water.
Your biological filtration media and plants do not need replacing. You let the wonders of nature happen in your tank and do the filtration for you (you let the beneficial bacteria colonize in your planted tank by doing the Nitrogen Cycle properly), as it is meant to be, not by using synthetic materials/chemical filtration media. Clean and clear water is achievable once your good bacteria are established, water parameters are stable, and you take care of your good bacteria by not killing them.
I would choose more space for my biological filtration and effective mechanical filtration rather than providing a space for chemical filtration media. In choosing a filter, you must be able to stuff a lot of mechanical and biological filtration. But of course, the smaller your filter is because you have a small tank, you cannot stuff more media since you have limited options for filters for small tanks. But as I said above, you can still experiment with larger filters as long as there are no hurricane flows in your tank.
But remember, everything submerged in your tank can act as biological media, regardless of its volume. From your hardscape (rocks driftwood), even the substrate you used, inside glass of your tank, any submerged accessories (intake/outtake of your filter, any submersible pumps, and surface skimmer, etc.), even the plants themselves and their roots, some are even free-floating in water, etc., can be home to your beneficial bacteria. Most are submerged in your tank!
My Canister Filter Tray Stuffed with Black Lava Rocks and Seachem Matrix during Filter Maintenance Keeping it Wet
Well, who doesn’t want additional features?
When you choose the best filter for your planted aquarium, you want to look for features that will benefit your faunas/plants and also you, the hobbyist, as well. Not to overcomplicate the process of filtration and not stuffing too many features or accessories that you may or may not need/use at all.
You want a filter that is easy to dismantle for maintenance, and you can access all the working parts. You also want a HOB filter or canister filter that is easy to prime, not by mouth. You want to stuff a lot of media in it, and you need a filter with more volume. And since it has more volume, the cleaner the water is, and the frequency of maintenance is farther apart. An adjustable flow/turnover rate is also a good thing to have.
Some filters feature easy access to a pre-filter, so all you need to do is clean or replace that pre-filter and never have to maintain or check your main filtration media or dismantle your filter until a couple of months. A filter that can be concealed and will not detract from an otherwise pleasant aquascape is certainly an appealing option as well.
Choose a filter that doesn’t have default media in its package so you can choose the most effective mechanical media and biological media that can home nitrifying and denitrifying good bacteria. This will save you with regards to cost too. There are alternative biological filtration media that are very cheap (sometimes free) but very effective, like lava or pumice rocks.
A filter that has aftermarket replacement parts or upgrades to its accessories is also a viable option. Of course, you have to choose quality from inside and out. The materials used, the quality of the impeller motor, avoid half-baked implementations, or “can do it all but master of none,” etc.
As I said before, do not compromise with your filter. A filter doesn’t have to be complicated. It should be a master of its sole purpose, and that is to provide excellent mechanical and biological filtration, and at the same time, provide flow and aeration.
Also, remember that the best filter of your choosing doesn’t mean it doesn’t need help. You can supplement it with other types of filters or mini submersible pumps to help distribute nutrients and CO2 across the whole tank.
There are filters with built-in surface skimmers, but if you want to replace them with a better one or decided not to install it (because they are not effective or don’t work at all), you can use a standalone one. I didn’t use the default outtake (spray bar) of my canister filter because I cannot point it in the direction that I want. So I DIY my way around using a duckbill then supplement it with 4 mini submersible pumps to create a circular (counter-clockwise) flow in my planted aquarium.
I know it’s cliche, but you want the best for your livestock and yourself as well. Your filter will be the lifeline of your planted aquarium, after all. And as you may have probably realized, this hobby is not cheap for the most part. Do not cheapen with your filter, and quality does not come cheap. Thankfully, there are many quality filters from known brands for a reasonable price range for each type.
The price of your filter goes with its size and the volume of your tank. So the larger volume, more powerful motors, and more convenient features from it, the costlier. You can also save by using alternative mechanical and biological media. For mechanical media, you can use foams with different porosities (micropore, mesopore, and macropore) instead of filter floss which deteriorates quickly. You can use foams for months to years, and I haven’t changed my foams for almost two years! I just clean/rinse them with old tank water when it is time to maintain my canister filter every month.
Hammering and Chiseling my Excess Black Lava Rocks as an Alternative Biological Media for my Canister Filter
For biological media, you can use small pumice rocks collected from someone else’s construction sand. They are also cheap for every kilo. You can also use lava rocks. In the Philippines, red lava rocks are cheaper than black lava rocks by half. Both are still very cheap compared to the commercial filter media available. Pumice and Lava rocks are inert – meaning they cannot change your water parameters – and both can home nitrifying and denitrifying good bacteria as they are very porous. I hammered the excess of my black lava rocks after hardscaping to make them smaller as my main biological filter media.
As we dabble over the considerations when choosing the best filter for your planted aquarium/s, we learned that our filter should not be overly complicated.
It should be a master of its sole purpose, and that is to provide excellent and effective mechanical and biological filtration appropriate for the size/volume of your tank. At the same time, it can provide water flow and aeration and some convenient features that will make the hobbyists’ lives easier and not make this hobby a chore.
We also discussed how you could save costs by using alternative filtration media versus the ones commercially available.
I hope you liked this article and learned a lot from it and if ever you have additional questions or want to share your experiences when choosing the right filter for your planted aquarium, just leave a comment below.
Next, we will be discussing the diverse world of lighting your planted aquarium.