--= MAK4 or Mag18 for closed loop pump? =--

[J Crew]

i have a 55gal and want to setup a closed loop system. i would like to use zero powerheads. which pump would you suggest i use to give me enough circulation so i won't need powerheads. i was thinking about either the MAK4 or Mag18. i'm thinking about using three strainers for my intake, then on my return using a t or y so that i can put a return at both corners. from there i will use another y and connect those flexable black things so i can direct the current. please let me know what pump you would suggest and any improvements such as maybe a spraybar instead or something. thanks

 

[Ricpan]

Howdy,
First off both pumps will work. The Mag will add more heat to the tank than the Mak4. The Mag is more likly to leak although they have improved on the pump housing and may have corrected this problem. The Mak will most prob last longer and handle back pressure better but don't let it run dry! I like flex PVC, unions both sides of pump, valves both sides, PVC "y", tank drilled back right and left with bulkheads, modular pipe with round nozzel on the inside. Tip use slipX male threaded 90 on outside of bulkhead uses less space. Use correct PVC cement for flex. I have a setup like this with tank back painted flat black, great look! "y" and 90's can be bought at www.plumbingsupply.com

 

[J Crew]

thanks for that info and advice. so you think that the MAK4 would be good enough and would provide enough tank turnover so that i would not have to use any powerheads? peace

 

[J Crew]

alright i've pretty much decided that if i'm gonna do it, i might as well do it right the first time. i've been reading all day long and have made up my mind to get two sea swirls on my closed loop project. i'm gonna get two 1/2" swirls for my 55gal. they are rated at 550gph max, so i think i'm gonna get the mag1200. it's rated at 1100gph at 4' of head. so i figure it will give me roughly 950gph with 8' of head. this will give me about 17x turnover an hour. i'm not going to be getting any sps coral for awhile, and when i do it will be a extremely limited selection, so i think this turnover rate should work. what are your thoughts on this setup?

btw... i'm going to get my 55 drilled tomorrow in the same place as the above pic. gonna get it drilled in two place (like above) and use strainers on the bulkheads. what size bulkhead should i use with either one of these pumps?

please post your thoughts on this. thanks

 

[somethings fishy]

The mag 12 pump loses pressure significantly with anymore than 4'-5' of head pressure. With 8' my chart says you would get barely over 700GPH. might want to upgrade.FWIW

 

[J Crew]

thanks for that info. do you have a chart that tells you what they put out at a given head? peace

 

[esmithiii]

jCrew- Remember that on a closed loop system that the height of the tank does not contribute to head pressure loss. Keep in mind that the only thing that affects head loss on a closed loop system is the length of tubing used, the diameter of the tubing and the number of bends in the tubing.

It looks like you have some 10 90° elbows and probably another 15' of PVC. Based on this, if you are using 2" PVC then your head loss is under 1'.

Here is a link to a good head pressure loss calculator:

Head Loss Calculator

When using the calculator, keep in mind that your vertical length is 0 due to the fact that it is a closed loop system. Enter all the length of tubing as horizontal. This is because the downward pvc is under pressure, which cancels out the vertical head loss. This is not so in a sump situation.

Ernie