External vs internal filters

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Mark Hewitt

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What are the pros and cons of each? I expect external is better for larger tanks?

I currently have a 17 gallon tank with an internal filter (Interpet PF2) would having external make any difference apart from not being able to see it in the tank.

Noise is a big issue for me since the tank is in my quite small front room the internal filter I have claims to be 'almost silent' but in practice it's quite noisy!

Would an external filter likely be more or less noisy? Especially considering it'll likely be shut away inside a cupboard!

One reason I ask is that I've been looking at
http://www.aqadvisor.com/
And it says that I'm likely to run out of filter capacity before I run out of physical tank space, so putting a more powerful filter on might help things, but there's no room for a bigger internal filter.
 
Internal filters take up too much tank space for my tastes. They are supposed to be rather quiet and cheap though.

There are numerous types of external filters. They're generally easier to work on and they take up minimal tank space. For a 17g, I'd recommend an AquaClear 20. Plenty of filtration and I hardly know mine is running.
 
Internal filters take up too much tank space for my tastes. They are supposed to be rather quiet and cheap though.

There are numerous types of external filters. They're generally easier to work on and they take up minimal tank space. For a 17g, I'd recommend an AquaClear 20. Plenty of filtration and I hardly know mine is running.

If I get an external filter I'd prefer it to be one which can be stored away in the cabinet beneath the tank, rather than a 'hang on the back' type.
 
canisters are a little pricier, but imo, better and cheaper in the long run. A fluval 205 would be about the biggest canister i would go with, but the nice thing about them is that you dont have to buy new cartridges for them. They have 4 sponges, and media trays.. you just rinse them in tank water every other week and thats that... but for a 17g tank, a canister is somewhat overkill, but will allow you to hide it under the cabinet, which im assuming is your goal
 
how are they cheaper in the long run?

for me the big pro and con is internal filters take up space and you have to see them others dont and add water. what exactly do you have in the tank? adding more and more powerful filters doesnt make up for over stocking the tank.
 
how are they cheaper in the long run?

for me the big pro and con is internal filters take up space and you have to see them others dont and add water. what exactly do you have in the tank? adding more and more powerful filters doesnt make up for over stocking the tank.

I have an internal Interpet PF2 filter in there which came with the tank. As I say I'm just going off the http://www.aqadvisor.com/ which reckons there would be enough physical space but not enough filtering.
 
but for a 17g tank, a canister is somewhat overkill

Strongly disagree. I love my canister on my 15g. I have a Jebo 835. I wouldn't buy that one again as 2 years on and the rubber parts have disintegrated, but I will always have a canister on it rather than an internal filter. I just don't like the fact that internal filters take up space in the tank.

My canister is as quiet as anything, I don't notice it. And it's not hidden in a cuboard. Other advantages are increased water volume, easy to clean, more surface area for bacteria. The 835 is meant for a bigger tank than mine, so I can over stock a little if I wish and it can handle it.
 
Do you have it below the tank, also where do you put the input and output pipes. I would imagine the inflow (out of the tank into the filter) would be at the bottom on one side and the outflow at the top on the other?

Would you recommend any particular canister filter for our sized tank? Are there any drawbacks to have a 'bigger' rated filter? e.g. I've been looking at the Interpet EPF 250, which is supposed to be for aquariums up to 250 litres (66 US gallons) would this cause issues with a 64 litre tank?!
 
Do you have it below the tank, also where do you put the input and output pipes. I would imagine the inflow (out of the tank into the filter) would be at the bottom on one side and the outflow at the top on the other?

Yup. Inflow on the left back corner and outlet is on the right back corner attached to a spray bar which is on suction cups at the back. The spraybar on mine goes just over 1 ft on my 2ft wide tank.

Would you recommend any particular canister filter for our sized tank? Are there any drawbacks to have a 'bigger' rated filter? e.g. I've been looking at the Interpet EPF 250, which is supposed to be for aquariums up to 250 litres (66 US gallons) would this cause issues with a 64 litre tank?!

No drawbacks to a larger rated canister, because over fitlered is still better than under filtered IO. The only thing I can think of that might be a factor is the faster flow rate creates more of a current so fish who hate a strong current won't like it. I have Rasboras and threadfin rainbows and they love it.

A 17g tank (roughly 65 liters) would do well having a canister such as the Fluval 105 which is for tanks up to 25g (100L).

But the mercedes of filters is the Eheim brand according to most. They're more expensive, but built to last, so if you'r serious, they're worth the investment. My mother's Ehiem lasted 10 years on her tank.

The Ehiem 2213 would be the one you'd want. It's rated for up to 55g.

My next canister will definitely be an Eheim.

Hope that helps
 
Thanks for that. I'll be a while before I'm getting one anyway but they seem to be reasonably priced.

One question, how will I know when my filter is overloaded and it's time to add extra filtration?
 
You generally buy the "amount" of filtration based on your tank volume. So if you bought one of the above, that's all the filtration you need for a 17g. And it will take care of all the different types of filtration. Biological, mechanical and chemical. You need all three for a good tank.

More on the types of filtration and different types of filters if you're interested.... Aquarium Filter and Fish Tank Filtration
 
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