Hydor Koralia 1650 Aquarium Circulation Pump, 1650 GPH - Original Magnum 5

I Bought two of the 3250 for my 150g saltwater tank. They are over kill for my tank. I should have gone with a smaller model. These things move a lot of water!!Mine are extremely quiet. They have a void space near the glass to lessen vibration. I don't know how to explain it. But they are very quiet and start up is smooth. I am going to get a wave maker so both of mine are not on at the same time, because at the moment my clown fish thinks he is on the EAC. ;)

I found it to be silent and moves water in a 75 gallon saltwater aquarium effectively. I just wish it was smaller. It is about the size of a softball.

5 months and it no longer works! Hydor, would I spend my money on another one of your products? One star is too high!

We've used this brand for quite a while in our marine aquarium. It works very well. Creates a lot of flow and is very easy to direct. We have ours set up on an automated on/off system which creates, effectively, waves in the tank. The magnetic mount makes it easy to adjust for best flow.

Too powerful for my 50 gallon.

Super powered powerheads!These work great in my 220 gallon reef tank, but I can't stand the click they make when turning on. If you don't care about an extra click in your tank, get these, they are awesome. If you can't, go get some DC controlled powerheads. I'm going to sell mine and get a pair of Tunze DC controlled powerheads.The other issue I have is, since they click and turn on so hard. They periodically fall off their mounting peg. I had to super glue them on to keep from falling down and shooting sand everywhere.Also, if you have a really thick tank glass like me (true 3/4") then you will need to call Hydor and see about getting a second magnet for each powerhead you buy. The single magnet they come with doesn't work as advertised.For the price, I'm happy, but will be happier when I'm not using a Hydor wave controller and have annoying clicking every 10-15 seconds...

This pump moves large amounts of water, and would be excellent if it were not for the extremely annoying noise it makes when starting up. I have it connected to a wave maker timer and every times it starts it has a period of very loud cavitation prior to settling down. With out the timer it would be good, but then would not create the alternating current I was wanting.

I have had 3 different sizers of these pumps and with my wave controller these are the first ones that I’ve had that didn’t make a clicking sound when alternating between the pumps.

This is a great pump that moves a lot of water..I just replaced my old one that ran for 6yrs 24-7..I highly recommend this pump to anyone looking for a lot of water movement..Also great company to deal with. thanks for everything!!