PssoppAquarium Wave Maker Powerful Powerhead, 360 Degree Aquarium Pump 3 in 1 Wave Pump for Fish Tanks 220V (ZY-100M)

I have a 230l tropical tank with red tail sharks and kissing gouramhi's, neither of which are small fish on a sand base, just setting the scene so you get the idea when i say this wave machine is quite powerful.i placed this in the middle of the side of the tank ad found it was too powerful for the fish as they were swimming near the top of the tank here as they prefer swimming in the middle or bottom if the tank.I then palced the machine about a 1/5 from the bottom of the tank and the fish prefered this postioning.It's quite entertaining watching the fish working out swimming into the wave then enjoying getting pushed back.The machine itself is very compact and silent , the only way i know it's working apart from the fish working out is the little sand dune appearing in the tank as the machine is pushing the sand along creating ridges.Excellent value for money and you fish will enjoy their work out.