After alot of good advice, i think all is well in my tank. I'VE GOT A 400 RIO, moved on the pleco, far to messy, the Midas has been moved on, far to aggresive. So we now have a red oscar who is Mr CHILLED out, a Texas, who now the Midas is gone, comes out of his cave, and I have added today a small shoal of Silver dollars. They all seem to be getting on fine and doing there own thing. Thinking of setting up a second filter to get it just right. Currently running an external top of the shop Eheim. What do you think. Would it be worth while ?

Thanks for all your help. Fab site !!

Any extra filtration you can add to a tank is a bonus and definitely worth while doing. Whereas it doesn't give you the green light to add lots of extra fish, it will definitely remove that waste quicker so your tank will be healthier. I run two Eheim 2028 external canister filters on my 125 gallon tank, each filter is rated up to 130 gallons, my tank stays clean for that much longer because of the extra filtration, I would always recommend putting as much filtration on the tank as possible if you are keeping Oscars, or any large fish.

I have a large Sump filter on my 300 gallon tank which has enough filtration for around 3000 gallons. May seem a little bit over-the-top, but it gives me peace of mind. If you can have the extra filtration, go for it

Thanks for the advice. Will get another filter sorted.

i agree with ofl you can never have to much filtration. i have enough filtration on my tank to do abut 800 gallons. i believe the trick is to not overstock, do regular water maintenace and filter like crazy.

I have got a small 20 gallon community tank that only contains seven very small fish, however, you'll be amazed how quickly the filter becomes completely filthy, and countless times I've come across people who use these type of filters with the Oscars. It's amazing how much crap is generated inside a fish tank, all that has to go somewhere.