Filters: Internal vs. External- pros n cons

Simple question time:

Can anyone please explain the simple merits and demerits of using an external filter as opposed to the \"one in the box\" on say a Juwel tank for a Tropical community setup?

Or what about an undergravel?

Is it a case of aesthetics? i.e. the box is removed and thus more space in the tank and no black column, but what about the heater

Is an external filter easier to remove, maintian & clean and is of benefit if access to the tank n lid is tricky (sitting on a kitchen counter under a wall-mounted press)?

I am looking at adding a 120 ltr tank (negotiated space restricts me to tank about 101cm len, 31cm deep & 46cm high), have thoughts on a juwel 120 and would like to get it setup from the get go in the best way possible.

Some threads say the external fluval 205 filter is good for a 120 ltr tank, others say eheim (sorry can't remember the model), don't know much about undergravel versions.

Beginners make mistakes, and sure it's all part of the fun of experiencing life in the water, but maybe decisions on the elemental parts of a tank setup at the early stage can really guide newbies and visitors to becoming active \"fissies\".

I know it's impossible to put it down as an \"if, then, else\" kind of statement but sure thats what we're here for.
Andrew

For 120 litre tank I feel an internal would be sufficient.

Hi Andrew,

unfortunitly the answer to this question is not clear cut there are various things that will effect the answer.

but the simple rule of tumb is YOU CAN NEVER HAVE ENOUGH FILTERATION


BUT FOR NOW I HAVE TO MAKE THIS SHORT SI WILL COME BACK LATER AND GIVE A MORE DETAILED EXPLATION

MICKEY

Externals in my view are better because:
1) you can add different types of filter media, this can do varius things but mostly improves water conditions but there are lots of different media to add, for example, carbon, media ceramics, pea etc.
2) have a larger internal surface so the good Bacteria stays in the filter helping to maintain a good balance in the tank, these little things help break down the bad Bacteria amd keep the water at a a better quality
3) Dont have to clean the filter as much, and internal you have to rince out alot to keep it from blocking, the externals shouldnt need cleaning any where as much, I tend to do mine once every 2-3 months depending on flow out put, this tends to at most a rince on the foam (in old tank water in the bucket as to not destroy the good Bacteria, and change filter wool.
4) They look better as all you see are the in and out pipes not a horrible box in the corner, you can also get very nice glass adapters for the in and out pipes which look fantastic but these will need more cleaning
5) If only gets hard cleaning a external when you strip it down and clean the pipes out but I only tend to do this once a year but then it isnt that hard.
6) Exteransl Will circulate the water around the tank better


Have a good shop around when looking around at the filters and different makes, i personaly dont like the Fluals as I had 2 x 404s in my time and the both leaked and have swapped to Eheim (which I find a lot better build quality but are a bit more expensive - but if you shop around you can get good deals PM me and I can tell you where I got mine online if you want), you can also get some externals what you can connect or have an internal heater atttached these are good as it will disperse the heat around the tank more effciantly than a heater and again improves the look of the inside of the tank.

When looking around at filters tey will recomend what size of tank to use this, you can easily 1/2 what they recomend as like mickey said you can always over filtrate but never under filtrate. the bigger the filter bear in mind the bigger the flow of water some fish love this but some fish wont (another thing to look at)

Hope this helps