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Cobalt Aquatics MJ Water Pump Multi-Purpose Powerhead (5W/7.5W/8.5W/20W)
We don't know when or if this item will be back in stock.
Brand | Cobalt Aquatics |
Color | Black |
Material | cotton |
Style | Submersible |
Power Source | Corded Electric |
Item Weight | 0.9 Pounds |
Maximum Flow Rate | 605 Liters Per Hour |
About this item
- Uniquely durable. The mj’s impeller uses a high-strength nylon infused fin-system that flexes to prevent sand, dirt, pebbles, etc. From damaging the fins and pump. Includes 3-year warranty.
- Extremely quiet and reliable. Made in Italy (same as original maxi-jet) and the quality of manufacturing is evident from the moment you turn it on. Cobalt’s MJ is one of the most reliable and quietest pumps on the market.
- Secure mounting. Triple Suction Cup mount ensures the MJ stays in place.
- Fully rotational and customizable for many uses. See product images for all the many MJ power head/pump Accessories and uses. Includes 6 foot power cord and cord guide
- Selection guide. See the product images to determine the best MJ size for your tank.
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Product details
- Is Discontinued By Manufacturer : No
- Product Dimensions : 2.75 x 4 x 8 inches; 14.4 ounces
- Item model number : 30001
- Date First Available : August 23, 2011
- Manufacturer : TopDawg Pet Supply
- ASIN : B005QRH57I
- Customer Reviews:
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Product Description
The Cobalt original MJ multi-use submersible and external pump and power head is built to last under the harshest conditions. Ideal for protein skimmers, wave makers, calcium reactors, nano aquariums, under gravel filters, terrariums and hydroponic applications. Made in Italy.
Important information
Directions
Ideal for wave makers, protein skimmers, calcium reactors, nano aquariums, under gravel filters and hydroponic applications.
Customer reviews
Customer Reviews, including Product Star Ratings help customers to learn more about the product and decide whether it is the right product for them.
To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyzed reviews to verify trustworthiness.
Learn more how customers reviews work on AmazonCustomers say
Customers like the quality, noise, performance, value, and flow of the water pump. For example, they mention it's well built, works great for the job, and is quiet in operation. Some appreciate the flow rate, saying it moves a lot of water quickly.
AI-generated from the text of customer reviews
Customers are satisfied with the quality of the water pump. They mention it's a well-built, reliable powerhead that is quiet and powerful. Some say that the fit and finish of all attachments are more solid. Overall, customers are happy with their purchase and recommend it to others.
"...This is a great, well-built pump that is a good fit as a replacement for the Biocube 29g stock pump...just don't expect a huge increase in tank flow..." Read more
"...Other than that, the pump seems to be well built and I would expect it to last for a long time." Read more
"...The product is very quiet, sturdy, and well made, much better then the Maxijet. This is Made In Italy, while the Marineland Maxijet is Made in China...." Read more
"...They operate less noisy than other brands, are very reliable, and have good head pressure..." Read more
Customers like the noise of the water pump. They say it's extremely quiet in operation, and generates minimal heat. Some say that the MJ900 has a dramatic reduction in noise compared to the original.
"...It runs very quiet and seems to run at the same temperature or slightly lower than the stock pump...." Read more
"...There is a dramatic reduction in pump related noise coming from the MJ900 vs. the original Coralife S-700 even though the MJ900 moves 27% more water..." Read more
"...The product is very quiet, sturdy, and well made, much better then the Maxijet. This is Made In Italy, while the Marineland Maxijet is Made in China...." Read more
"...That was 10+ years ago. They operate less noisy than other brands, are very reliable, and have good head pressure..." Read more
Customers like the performance of the water pump. They say it works great for the job, is the best working powerhead they've found, and is really happy with its performance. Some mention that the pump seems powerful and has good output. Overall, most are satisfied with the performance and recommend it to others.
"...It has good output as well, so ultimately this is a GREAT pump for the 29g Biocube...." Read more
"...I bought this pump to use with my water chiller, and it has been working great!..." Read more
"...I ended up connecting #7 to #2 and it works great. It's just a little shorter than I'd like. They still deserve a 5 starts...." Read more
"...I use mine to suck water through a big Eheim sponge pre-filter. Works like a charm..." Read more
Customers like the value of the water pump. They say it's well worth the money, a reliable pump for the price, and a great purchase. Some customers also mention that it works well for the money and is worth the wait.
"...Would I use one for a sump pump in a basement - no. But a good reasonably price makes them hard to beat.I just ordered a couple more...." Read more
"...So far, worth every penny" Read more
"...Fortunately this was able to work.. unfortunately this is extremely expensive for this size of a pump..." Read more
"...Powerful, and more importantly, silent. Well worth the few extra dollars. Go ahead, spoil yourself with this first-class power head/Pump." Read more
Customers are satisfied with the flow of the water pump. They mention it provides a strong water flow, it's quiet, and it moves a lot of water quickly. Some say that it'll increase the flow inside their aquarium. Overall, most are happy with their purchase and recommend it to others.
"Has a very great flow, I love this pump because it is very universal and you could use it for quite a number of things...." Read more
"...Perfect amount of flow. Very versatile with an adjustable outlet angle. A very nice accessory kit comes with it and it's very quiet...." Read more
"...While the MJ600 provides fairly reasonable water movement for their size, I do wish I'd have gotten a slightly larger version...." Read more
"...The circulation also helps move detritus to the filter intakes. My favorite feature of this powerhead is the venturi...." Read more
Customers like the accessories that come with the water pump. They mention that it runs completely silent, has several accessories options, and comes with all the accessories you will need for multiple settings. Some appreciate the mounting pieces and customization parts. Overall, customers are happy with the accessories included with the product.
"...Very versatile with an adjustable outlet angle. A very nice accessory kit comes with it and it's very quiet...." Read more
"...heat unlike some other powerheads, and there are enough fittings and attachments in the box that one can set these up in just about any..." Read more
"...This one was exactly what I expected. it comes with a lot of mounting pieces that I do not understand...." Read more
"...TO SAY THE LEAST THEY ARE SIMPLE AND VERY WELL BUILT. THEY COME WITH ALL THE ACCESSORIES YOU WILL NEED FOR MULTI SITUATIONS BEYOND USING THEM AS..." Read more
Customers find the installation of the water pump to be easy. They mention that it's simple and well built. Some say that the pump does not come with instructions.
"...the third chamber where the stock pump resides, so I had no issues getting it installed...." Read more
"I PURCHASED TWO OF THESE PUMPS IN JULY 2012. TO SAY THE LEAST THEY ARE SIMPLE AND VERY WELL BUILT...." Read more
"...Easy to maintain. Don't short cut to save $$$. The others will never last the same or they will rattle." Read more
"...I just used the mounting bracket and suction cups. there are no instructions of how to use the other mounting pieces...." Read more
Customers are mixed about the size of the water pump. Some mention it fits perfectly in their skimmer box, and is a good fit as a replacement for the Biocube 29g stock pump. However, others say that it is way too large for this application in a small tank, the hoses don't fit, and the parts don''t cross fit.
"...This is a great, well-built pump that is a good fit as a replacement for the Biocube 29g stock pump...just don't expect a huge increase in tank flow..." Read more
"...it as an extra flow pump in the display area, but it is way too large for this application in such a small tank...." Read more
"...All pieces fit together well. The only big difference is the propeller shaft is metal, not plastic...." Read more
"...Superb fit and finish to all the pieces, would recommend." Read more
Reviews with images
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Top reviews
Top reviews from the United States
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Some pros...the outlet of this pump is the same as the return pump. You will want to purchase a new piece of tubing as the original piece will have been stretched out a bit due to the tapering on the stock pump. In addition, the pump fits nicely into the third chamber where the stock pump resides, so I had no issues getting it installed. It runs very quiet and seems to run at the same temperature or slightly lower than the stock pump. It has good output as well, so ultimately this is a GREAT pump for the 29g Biocube.
However...one important thing to note is that the increase in output is not really all that noticeable. I created a video showing the movement of my corals before and after replacing the stock pump and the difference isn't really all that significant. I will be giving the MJ1200 5-stars since it is a great pump, but if you are a Biocube 29g owner and are hoping this will make a drastic change in your tank, lower your expectations a bit!
This is a great, well-built pump that is a good fit as a replacement for the Biocube 29g stock pump...just don't expect a huge increase in tank flow after installation.
I never had any problems with my Maxijets!
Pros:
Comes with short or long impeller screen. The long one is for stuffing the screen inside a foam filter to microscreen the imput, nitrifiying bacteria will inhabit the sponge (which is a good thing of course). So if you do use a sponge of some kind, only clean it in a bucket of old tankwater (so you don't wash off those bacteria with tapwater, they are keeping your fish alive).
Comes with an infuser tube. This silicone type flexible tube runs from outside the tank to the output tube of the powerhead and produces a bubble stream, thus putting oxygen in your tank. Fish need oxygen, and more of it when the water is warmer. It can save all your fish alive if you have a heatwave and don't have an air conditioner that is working for your house.
That diffuser has a little valve with continuous adjust to control how much air is infused, in other words how much of a bubble stream of air you wish in the output of the powerhead. You can adjust it all the way tight for no bubbles at all if you want. At max there is a powerful bubble stream.
This saves you from needing an airpump and stones to infuse oxygen into the tank. And an airpump below the tank can siphon the whole tank full of water down on your floor and carpet and into your living room walls, doing major damage. But when this powerhead is infusing oxygen, that can't happen as long as you keep the air infuser tube above the water line. So feed it up through a tiny hole pointed straight up out the tank. It is only 1/4" tube so not unsightly.
Has a flat diffuser on the output tube (removable) to spread out the water flowing out to reduce the current in the tank so it does not jetstream so swiftly.
Cons: The water flow out is not adjustable (the Eheim brand powerhead pumps can be set continuously from half to full output gallons per hour).
That infuser tube (airline tube) to make bubbles uses a non standard size air hose which is slightly bigger in diameter than the normal 3/16" that most air pumps use. So don't lose the hose that comes with this powerhead (I believe it is 1/4" instead of 3/16"). My 3/16" tubing would not fit onto the fitting but the tubing that comes with the powerhead does fit.
That infuser tube (airline tube) is black. A clear color is easier to hide outside the tank, but easier to see inside the tank. You could put a 10 cent airline splicer and splice the black tube inside the tank to a clear tube outside the tank.
I see no reason for less than 5 stars for Cobalt Maxijet powerheads :) !
I decided to purchase a Sicce, Tunze, Eheim or a Cobalt Aquatics pump (made in Italy). A source that I trust recommended the Cobalt Aquatics MJ900 (230 gph) pump to begin with. So, it arrived yesterday and I installed it today. There is a dramatic reduction in pump related noise coming from the MJ900 vs. the original Coralife S-700 even though the MJ900 moves 27% more water per hour than the S-700!
Note to Coralife BioCube 14 owners: When the suction cup & mounting brackets are attached to the MJ900 the assembly will not fit into the available space in chamber #3. What I did to isolate the hard shell of the pump somewhat from any direct physical contact with the aquarium structure is this: I took the three suction cups and stuck one against the bottom front, rear and left sides of chamber #3, thus creating little rubber stand-offs against which the pump could rest. Then I cut the return hose just short enough that it suspended the pump off of the chamber bottom, again to eliminate direct pump to aquarium contact. There is still a hum associated with this arrangement but much less than what it was with the S-700. Since I would like the aquarium to run as silently as possible I will probably at least give the other pumps mentioned a try over time. For now, the MJ900 has successfully reduced the hum to an 'acceptable' level. I withheld the fifth star because it doesn't run silently which is what I was hoping it would do. Other than that, the pump seems to be well built and I would expect it to last for a long time.