Jake’s Planted Aquarium Pages

There are so many ways out there to filter a planted tank, ( or any aquarium for that reason ) , but some seem to be better than others. I will go over the basics and a few types of commonly used planted tank filters.

Types of filters:

Canister filters - My absolute favorite for filtering a tank 29 gallons or larger. They are basically an enclosed “bucket” of sorts that uses a pump to push water through different layers of filter media inside the “bucket”. They usually come with all sorts of different options from spraybar outflows , which are basically a tube with holes through which the water comes out, to quick disconnects which shut the flow off to make cleaning out the filter easier. My favorite brands are the Eheim series , which are expensive but of excellent quality, and Rena Filstar XP filters, which are also good quality but cheaper. They typically sit under the aquarium inside the stand and tubes then go from it to the tank which serve as the intake and water return ( outflow). This set up allows for quite a bit of customization as to how you want the water to flow in your tank. It also allows for the most customization of filter media. My favorite water return method is to use the spraybar, but to submerge it in the water. It keeps the flow fairly spread out and more gentle to fish and tall plants you may have.

Power filters - Also known as “HOB’s” or “HOT’s” ( Hang-on back and Hang-on Tank , respecitively). They get their name by being filters which , surprisingly enough, hang on the back of the tank. There are many types available, but I’ve found Hagen’s Aquaclears to be among the best. They offer good sponge filter media that can be rinsed and reused instead of throw away ” cartridges” , are very quiet, and are fairly cheap.

Powerhead filters - For many different brands of powerheads, they make attachements to turn them into kind of a “quick filter”. One kind is Hagen’s “quickfilter” that allows you to attach a water polishing pad cartridge to an aquaclear powerhead. This is great for general water movement and water polishing, i.e. removing turbidity, or suspended gunk in the water. Marineland has some rough sponge attachments for some of their powerheads that makes for a good general biological and mechanical filter. These are usually used in conjunction with either a canister filter or power filter.

Sumps- Just like the reef keepers use. It makes the inside of a tank look a whole lot cleaner because your water is going down into a smaller tank or container undernearth the tank stand and you can put all your stuff into it. By stuff I mean heaters, ph controller probes, thermometer, and everything else that would normally be cluttering up the inside or side of your tank. A drawback is the amount of co2 they cause to be lost, but co2 is cheap so if you have pressurized co2 you can just crank it up. I wouldn’t recommend using a sump in a tank you plan to use DIY co2 on.
All other filters ( sponge, Under Gravel Filters - UGF’s , Reverse Under Gravel Filters - RUGF’s , air powered filters, etc : I intentionally left these out . Some would not agree with me, but I don’t view them as ideal for planted tanks for the most part. They all have their niche and I’m not trying to downplay their usefulness, but they can be problematic or just simply underpowered for planted tank use, in my opinion.
Ok, so that’s a few types of filtration. What do I need to know about them?

First of all, there is a difference between water flow and filtration. How many gallons per hour a filter pumps out does not equal filtration. How much water per hour passes through the filter media does. That sounds confusing, but please keep in mind that some filters , such as el cheapo canister filters, allow for water to bypass the filter media. If the water is not going through the media, then it’s not being filtered. Also, it’s important to know that what size tank filters are rated for doesn’t mean that it’s all you need to filter that size of a tank. This is where water flow does not equal filtration comes into play. A canister filter pumping 217 gallons per hour, (gph), that is rated for a 75 gallon tank, will not be enough water flow for a 75 gallon tank. That isn’t even three times the total volume of the tank being filtered in one hour. Even more interesting is that the force at which that 217 gallons is being returned from the filter might not be enough to give you proper flow in the tank. Without proper flow, you might start seeing stagnant areas where gunk and fish pooh just accumulates instead of being caught and sucked up by your filter. Plants in the tank might add to the problem by blocking most of that puny 217 gph flow.

Also, if you plan on injecting co2 at some point, please know that if you purchase a filter that has a biowheel you will be removing the biowheel at some point probably in order to keep it from outgassing your co2. This also goes for any filter which bubbles in any way, or causes water to “crash” as it moves the water.

So, how much flow do I need already? Most people would recommend water flow and filtration combined to turnover at least 5-7 times or more the total volume of water in your tank. In a 75 gallon tank, for example, a 300 gph canister filter and a 200 gph powerhead would give you 500 gph. That would move the total volume of water your tank can hold over 6 1/2 times in an hour. You can use spraybars, special diffusers, point the powerhead flow into the back of the tank, and so forth if you have fish that do not like that much current, or fish that would be pushed around by that much.  It’s all about diffusing the flow so it’s not coming out of the filter or powerheads in one powerful stream.