I have just introduced a Hydor Koralia 3 Power Head to my 350 litre tank and found the results are great.

My tank has an 8 inch Oscar and 6 clown loach, which seem to love the movement of the water created by the head.

The tank never really had much movement around the surface and as such, not as much oxygen as the fish and i would have liked.
After adding the Power Head the results were immediate. The Oscar is much more interested in everything moving around the tank alot more and looking much happier in itself.

I watched the Clown Loach last night via a Blue moon led system i got from ebay and they seem to be much happier too.

I always thought these systems were for marine tanks but decided to take a chance on buying one after reading articles in Practicle Fishkeeping Magazine.
Yes it was expensive at £69.00 at my LFS but they are
available cheaper on the net and do a fantastic job of moving 3200 litres of water per hour.

Maybe it's not for everyone, but i recommend it to anyone who would like to oxygenate their tank more.

before using powerheads to circulate the water it is advisable to re search the sort of conditions the fish you have live in. Oscars and clown Loach, will live in slow-moving rivers. Fish that prefer Stillwater might not appreciate a very strong powerhead causing lots of currants in the water.

I Use a large sump filter on my 300 gallon tank so I use an Eheim 1262 powerhead. I've actually got 2 in the sump that only use one as it is quite adequate. I've got inlets at both ends of the tank butt using both of them at the same time causes too much commotion.however, it's good to have a standby in case one of them breaks down

www.charterhouse-aquatics.co.uk/catalog/...400-ltrhr-p-268.html

So are you saying i have done the wrong thing by introducing a power head into my tank?
I have researched these fish thoroughly and extensively and found very conflicting information from my LFS and the internet.
If we believe everthing we read and do as we are told, we would actually do nothing and never keep fish at all.
What i have found over the years of keeping fish is that no 2 fish are the same and no one has the same tank or conditions, so what may not be right for one may be perfect for another.
Everyone i have spoken to in the fish business in very non committed and will never say that this or that will definately work.
So i try new things and they either work or they don't.
My fish are very happy in the environment i have spent a great deal of time and money creating for them.
All aquariums require oxygen and the powerhead i have installed has given the tank (in my opinion) a great lease of life and as i said before "the results were immediate".
So i am happy that i am providing my fish a very good environment for the species i have chosen.
And to use your words " You may not be right." But who knows really!!!

I don't think I said you were doing the wrong thing. I would tell you if I thought you were.if your fish seemed fine, then I shouldn't worry about anything.