Don't belive everything you read on the internet, he should be able to explain how he figure it is pushing 2500 gallons.
Hi My name is Ryan . I am the owner of
www.MJmods.com Figured I'd let you know how we came up with these numbers : )
The testing method we use is really simple and has repeatable results by not only me but many people who have also done it. After talking to some of the pump manufacturers at this years macna it sounded like they use some very similar methods of testing.
(this is much easier to do with two people, one for the timer and one for the pump)
basically you find a large reservoir of water like a pool, hot tub , bath tub and fill it with water. you then take a garbage bag and wrap it around the mouth of the pump and submerge both. You then turn the pump on for a designated amount of time like 10 seconds. (be careful not to put your hands over the inlet slits)Pull the bag out of the water and measure how many gallons of water the pump pushed into the bag. There is zero pressure on the bag to fill with water and it will stay empty pretty much indefinitely without turning on the pump. This testing method may be off a small amount because of the short time intervals but we were looking for general numbers and being off by 50-100gph isn't really a big deal i guess. It is generally thought the the pump probably does more but because it's hard to hold the bag on without covering some of the inlets the testing results in slightly lower numbers. there is also some back pressure that forces some water out the sides of the unit and makes the flow rates lower with this test but i have no idea what extra GPH that would equate to .
anyways we came up with 1600 gph for the 900 with a 1435 and 1900-2000gph for the 1200 with a dumas 3004. a few things will effect this like the amount of fraction/quality of your build and the number of inlet slits you cut. this is a link to the part of the RC thread where i did my testing but you can find other peoples similar results scattered throughout that huge thread.
http://reefcentral.com/forums/showthread.php?s=&postid=7946765&highlight=tub#post7946765
if you doubt it, put a modded one next to a unmodified one and feel the difference. keep in mind on the stock MJ the flow is coming out of a 3/8" hole and the mods have a huge outlet. the difference is shocking if you put the dispersion plate on the stock mj so the flow is spread out a bit. Keep in mind that this project is not a brand new idea and it has been around for quite a while. the thread above has split 4 or 5 times and last i checked had thousands of posts and well over 100,000 views. the 2000 GPH figure is the general consensus from all the people who have built them , long before I started supplying parts for the project or anyone had any type of commercial interest in the project.
here is a video of one in action posted by an RC member. Obviously this isn't very scientific but while you are watching this try and imagine how many MJ's it would take to create that much flow.
http://video.google.com/videoplay?docid=7159313810789461735
here is a video of how to make one with the old style impeller
http://www.reefvideos.com/reefshowcase_04_content.html
BTW i think the 2500 gph number is a bit high . the octura 1440 with the mj 1200 "might" get close to that but i doubt it and my luck with that prop is 50/50 at best. most of them with that prop need to be jump started by bringing the MJ to the surface of the water.
if you have any questions please feel free email me at
[email protected]
