Internal Filter Too Strong

Hi all Yesterday I decided to upgrade my filter for my bigger tank so I bought an internal filter which attaches to the glass on the inside of the tank. It said on the box that it's designed to be used in tanks which are up to 150L in volume and my tank is 140L. I've placed it on the other side of the tank to the one I have at the moment, which is designed for tanks up to 60L, with the aim to run them both for a couple of weeks until this new one establishes it's own colony of bacteria. When I turned it on however, it almost pushed my poor fish into the glass on the other side of the tank because it was so powerful. I turned it off for the night but turned it on again this morning and left it running for a few hours (turning my other filter off) to see if my fish would adjust. My cories absolutely love it and are still playing in the current but all my other fish are hiding at the bottom of the tank, obviously uncomfortable. Is there a way I can reduce the flow? Or will my fish get used to it if I give them time?

It's a tankmaid filter. I've never used the brand before and I thing they only sell it in New Zealand and Australia. I've got it attached to the side wall in the cprner, facing along the tank. Would I be better to move it maybe so it faces forward? I positioned it like I did because I was trying to get circulation through the whole tank.

Ooh both such good ideas! I might actually give the sponge a go because it'll look a bit better. Thank you; you're very smart

Lol i just got a spray bar and it's working so well still on the strong side but the fish are a lot happier

I have a tank maid pro 1500 , you can't buy a spray bar for it the outlet is in the middle of the unit and this internal needs to be fully submersed and the ones ive wasted money on from Ebay don't fit
but i have found a solution , get the filter and activated carbon replacement kit , they cost about 6 dollars AU
the top canister ( there are three compartments) is empty , use one filter in that empty top bit add a second black sponge filter to the middle and to the bottom add the filter media bag , its slows the current down enough that your poor fishes no longer feel that they are in a whirlpool.