i am currently housing my oscar in a 120litre tank and as he/she is getting bigger by the day (about 8-9 inches)know this isnt big enough and want to move it quick. i have been offered a 180l juwel tank at a bargain price and as money is short i am very tempted to take it, however- these tanks come with the compact filter systems built in and was wondering if they are any good or am i going to have to go out and buy a external filter as well?

My personal opinion is no, the jewel filters are not up to dealing with messy fish like Oscars. I had a Trigon 350 a few years ago and the filtration would become clogged very easily. This is one of the larger tanks and they utilise three sponges. It doesn't take very long for the sponges to become absolutely saturated with crap. If I was you, I would get an external filter if you want to keep Oscars. The problem with the jewel aquariums is I don't think they have any cutouts at the back to feed the pipework in. You would probably have to customise the back of the tank yourself so that they can take all the pipework that comes with external filters. I don't think it would be that difficult, just putting in the holes for the pipes to go through.

I agree external filters are needed when keeping oscars. The price of an external filter is a lot more than the equivalent internal filter(in terms of gallons per hour water turnover). When it comes to filters external cost more for a reason, they do a much better job


However if money is tight, buy the 180l and run it with the filter it comes with and the filter you are using on your 120l until you get the money for a big external filter (get the top end size eg if you get a fluval get a fluval 505- you cant over filter). You could also look in the classified or e-bay for a second hand filter(again biggest is best). Im sure adapting the tank lid to allow for pipework cant be that hard

Oscar's like pleco's are messy fish - so you will need an External filter, I have a very heavily populated Juwel 190 and the filter needs cleaning quite regular. With my Juwel 190 I use an Eheim 2128 external - which I alternate with an Eheim 2327 Wet / Dry filter (shortly to have Penn's Eheim 2329) I also use 2 Fluvel Powerheads as well to remove the Nitrate / Phosphate / Soften the water. The other Fluval has active Carbon in it. I use other equipment to purify the water but you won't need this for keeping Oscars. Am not sure if Oscars like water to move around alot but as they are quite messy I would advise that a powerful filter is used to keep the water clean as it may start to look mucky and would probably smell after a short interval. Anyway yep external filters can be used OK with Juwel tanks but you may have to cut out the lid a bit but these lids can be purchased quite easily if you decide to sell your Juwel tank at a later date. Rgrds Nige AKA Nippienige