Hydor Koralia Nano Aquarium Circulation Pump, Includes Built-In Cable Protector, 565 GPH, Measures 2.4-Inches & is Ideal for Fresh or Salt Water Use

I got the smallest option for my 5 gallon tall. I have a heavily planted tank and my water pump was continuously being clogged with algae and the flow would be so low that my fish were unhappy and the algae was out of control!Since adding this wave maker, my algae is in check and my fish are so happy! I was even able to delete the pump entirely because with this, there was no need for one anymore. I just drilled a hole into the filtration area so water can be drawn through by this wave maker.Be sure that your fish are compatible with high flow rate. Mine are but I can see how other fish might really get pushed around and become stressed.

Just ordered 2 of the Nano 425's for my 20 gallon long Shallow Lagoon mixed Reef Tank full of corals. It was the perfect size and gave me the right amount of flow in a tank this size for corals. I have paired it up with their Wave Maker and my corals should be much happier going forward with the increased random flow this combo gives you. Been using these power heads in my Reef Tanks for years where I needed a functional, lower cost option that gets the job done.

This size is perfect for my 5 gallon marine tank. The water is moving about and none of the corals or my shark-nosed goby ("Little Guy") seem distresssed.

I previously had the smaller unit and upgraded to this 425 GPH rate Hydor Koralia Circulation Pump and must say I like this one better. These units work well and are easy to clean.

240 GPH is perfect for my 55 gal tank, my GSP loves it. The previous one we use was 500 GPH, and that is a bit too intense for our puffer, stressed him. 240 GPH creates a much smooth and softer flow. The magnet design is great. Power cable is long enough. The only con is the adapter design, it doesn’t hold the head so well. It’s too loose. It’s hard to lock the fan to blow the angle I want.

Thanks to the reviews, I decided to give this pump a try for my 9 gallon Eheim Aquastyle saltwater nano. I've been in the hobby over 10 years - mostly heavily planted, aquascaped freshwater tanks in the past from 50g to 0.5g. I've always been very pleased with the Hydor products and this one is no exception. For the quality, price and function, this is a great pump, especially on Amazon. I wouldn't go cheaper with a more inferior brand or even a more costly one that does the same thing.I found other reviews with tank descriptions especially helpful so here's mine: my saltwater nano has 1 clownfish, 1 cleaner shrimp, cuc's and several soft corals of starburst polyps, kenya tree, pulsing xenia and mushrooms - live rock and 1 inch live sand (sand is more aesthetics). Eheim's tanks are beautiful on their own, so every accessory counts going in. Most importantly, I didn't want the other inhabitants blown in a circle or with such force that they would have to hide in a corner of rock. Sure enough, based on the reviews and other research on fish boards, the open flow of this pump is gentle enough in the tank for everyone. Based on my live rock formation, I have the pump on the back left side, a little lower than mid-tank directing current toward the opposite wall with the corner filter (sand gets kicked up if placed lower). The pump creates a soft current that wraps nicely around the rocks to give the corals a gentle sweeping effect in combo with the filter flow overhead. The starburst polyps have already grown larger in the past week and the CUC's are out and about more often in the light. Another benefit is that the sand has been cleaner too, even as I increased my light hours for better tank viewing in winter.Since I have only had the pump 2 weeks, I am giving it 4 out of 5 stars. As other reviewers mentioned, there is a slight hum to my otherwise nearly silent tank. But the animals all seem more lively and "happier" with the added flow so I'm keeping it. If the vibration gets much louder or circulation fades, I'll likely replace it with another one. Hopefully the sound remains minimal and pump lasts a couple years. If so, I would vote 5 of 5. Cheers and happy reef/fish keeping!

I bought two of these 425 GPH circulation jets for my 40 gallon saltwater cube tank. I found it easy to install the plastic suction cups to the plastic ball on the unit by first placing the suction cup on the tile floor, and then wetting the cup opening and plastic ball with a small amount of saliva (yes gross but it works), and then firmly pushing the ball straight into the plastic suction cup socket. Once in the tank, I placed one unit in the front right side, and the other unit in the back left side to create a clockwise flow. They are placed mid depth, and angled towards the glass. These locations works great for both fish and coral. I also did not press the suction cups on the glass to hold the units in a static location, as the magnets are strong enough to hold the units from the outside of the tank without pushing the suction cup onto the inside of the tank wall. This allows me to move the jets time to time to create varying flows for the fish and corals.One thing to note is that these units, like any motors inside your tank, will add additional heat load to your water. I have a small fan blowing across the top of my tank set on a temperature switch, which increases the evaporation rate and quickly cools the water when the temperature rises above my limits. The fan was 1/20 the cost of any decent chiller unit, much quieter, uses minimal energy and allowed me to use the saved money to buy an ATO to keep the salinity at a constant level, and keep the tank topped off with the additional evaporation load.In summary, the engineering is sound on this circulation jet, and the price is fair. Just be careful installing the suction cup to the plastic ball pivot...

Me gusto el precio

Great value for the money! It's been running in my aquarium for a few months now and it works great to create more water movement and eliminate dead zones.

I bought this 240 GPH for my 29 gal but it doesn't seem to push much water around. It'll probably push water like half the width of the tank and that's about it. Don't get me wrong though, these pumps are amazing, but like the top reviewer said, make sure you get some big and suitable for the size of the tank.I'm goiing to buy 1 more of these powerheads but maybe 1 size up.

perfect for a little 10 gallon tank

To start my review I would like to state that even though a power head says its for a 20G tank and you have a 20G tank, doesn't mean you can only by one power head and be like "Yay, I have flow everywhere!". You need more than one to achieve appropriate flow through your tank, especially if you are hosting corals. If hosting corals you need to have at least 30x the flow vs volume of your tank. So if you have a 20 gallon nano you would need at LEAST 600 gallons per hour of water movement.I have seen people complain about the tank ratings post by Koralia saying they are inaccurate but I beg to differ. The ratings are there to guide you which power head provides USEFUL FLOW WITHOUT POSSIBLY UPSETTING INHABITANTS. With that said, I have had experience with all three Koralia nano power heads so I will be reviewing all three.---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------All three pump generally are designed the same way. I find them very reliable and quiet but they can click when they start up so using them with a wave maker can be annoying. The magnetic mounting is probably the best feature. No more suction cup issues here! You can even slide the magnet on the external side of the glass to move or adjust the location of the pump. These magnets are STRONG so be careful not to let them slam up against your glass! Directing the power head is a little meh. The amount of tilt you get is limited and the power cord works against you and gets in the way. They all come apart the same way and are generally easy to clean. Now for the individual remarks......First up is the Hydor Koralia Nano 240!!! This pump is pretty timid. It could be used solo in a 5 gallon. For a 10 or 15 you should consider getting 2 unless you are getting some decent water movement from another source such as a Hang-On Back Filter. Another useful feature is to simple remove that one annoying dead spot in larger tanks. They are small and can be nicely hidden from sight.Second up is the Hydor Koralia Nano 425!! This is a sweet little pump and works great for water movement. I had three ( an example of needing more than one which came out to 1275 gallons per hour ) in a tall 25 gallon marine tank and they did a great job! From personal experience I wouldn't used these in a tank longer than 24" like a 20 gallon long ( 30" long tank ). It can't really reach far enough to the other end.Lastly is the Hydor Koralia Nano 565!! This a new nano pump from Hydor, The pump basically looks like a 425 but with some mods to push more water. It works fabulous and if you have a 20-40 gallon tank, I would skip over the 425 and go straight to these. The extra flow is worth it, especially if your tank is of the marine type.Overall these pumps are great. They run quiet and don't need lots of maintenance. There are fancier pumps out there for sure, but spending $50 on these versus $200 on those, these pumps are a win.