mag 18

[paramediclane]

i have a 90 gallon reef ready with one corner overflow. currently running a little giant 3mdsc rated at 750 gph. i aquired a mag 18 pump which i ran inline since the plumbing was already there. the decrease in water volume was incredible. there are only 2 90 degree bends in the plumbing and only about 4 feet of height. my question is why is a pump rated at 1800 gph putting out less than a pump rated at 750 gph when the same plumbing is being used.???? the only thing i changed was the pump itself...

 

[ChrisRD]

The Mag pump performance claims are WAY overstated IMO. That said, it sounds like something could be wrong with your pump because a Mag 18 should be putting out plenty of flow in that configuration.

 

[Len]

Did you figure out what was wrong with the pump? I've seen MAG 18's and I agree with Chris' assessment that - although overrated in terms of output - are quite powerful and should be just as powerful (if not more so) then a 3mdsc. Something doesn't sound right about the pump.

Oh, BTW:

 

[paramediclane]

well i cleaned the pump inside and out. i then hooked up 1.5" flex tubing to the pump outlet and ran it. the output appeared to be alot. i did all this outside in a 5 gallon bucket. i am using 3/4" flex and pvc in my plumbing. maybe i need to upgrade to bigger plumbing even though the output on the pump is 3/4". this pump drained a 5 gallon bucket in mere seconds. i just hate to tear out all of my plumbing only to find out that it isnt pumping the volume i want. i also have a 3/4" return bulkhead in my overflow, so would it even benifit me to upgrade the rest of the plumbing.?? any help is needed, thanks,,, lane

 

[paramediclane]

hello all, i think i finally realized what is wrong with my mag 18 on my 90 gallon. I used 1/2"plumbing.!!!!!! i cant believe it!!! i am so stupid... the little giant uses 1/2" plumbing and i just continued using it for the mag 18. the mag 18 has a 3/4" outlet and they recommed at least 1" plumbing. i guess it will be another day of "tear out and rebuild" tomorrow. hopefully it will blow the fish all over the tank. lane

 

[danmhippo]

(LOL)!!!

1/2" piping will do "that" trick to your Mag 18 alright.......

Better go with 1" piping, at least......

 

[paramediclane]

i sure do feel stupid. its amazing how such small and sometimes unnoticable things can make one cuss so much.

 

[Tankless in Dubai]

I am just about to install a Mag 1800 on the new tank that I have been planning forever...

I am so grateful for the information and experience shared here. Thank you everyone. This info on the Mag 1800 is so invaluable to me as I am working so hard to get it right from the start.

Grateful...

 

[paramediclane]

im glad my screwup can help you out. good luck in setting up your new money pit. and by the way, be sure to come to this site for info first, therefore you can get what you need, and not what the lfs wants to sell you.