ok so i'm in the planning process. and i don't like to skimp on anything. if your going to do something right, do it right the first time. i know you want as much flow through your tank as possible. it looks like i will be getting a 120 gal. w/ 40 gal sump and probably going to run the sump a little over half way so like 25 gals extra. so with that making my total volume 145 (150 maybe). and i know you want to turn that volume over 10-15 times. making that 1500-2250 gph.
now one of the LFS guys told me that he turns over his tank about 35 times. but he has a 40 gal tank. that seems to me like way too much flow for a tank. but i know more flow is better for your corals.
well here's the question. the MAG 36 will pump around 2800gph at 5 ft head. is that too much flow for a 120 display tank? (here: 48x24x24 if the dimensions matter at all) i would be turning over the tank 23 times. 23 times isn't as much as the guy at the LFS said he was running on his tank at home. but 23 times is near twice as much as i ever read about doing.
another question is - i know i can throttle the pump back to control the flow. but will me throttling back the pump lessen it's life-span? and i know a little tweak with a ball valve will be just fine. but it i throttle the pump down to half the output will i be seriously killing my pump? if i would be then i would be better of with a smaller pump right?
i was also thinking about doing a manifold and having many returns. as i will have 2 return holes. but then i can run more return pipes else where in the tank. like a spraybar the length of the tank under the liverock to help with circulation. anyone have experience with a manifold and a spraybar?
sorry for so many questions all at once. i just wanted to figure this out before i order a pump. and i for sure don't want to get the wrong one and have to return it. i might be getting my tank on my birthday on the 6th (i have a good gf) so i want to get started right away. finishing up the final plans. thanks for any help.
I throttle back my Mag7 and with my plumbing technique have always had the option to do so. I've owned it for 5 years now and it's still going strong.
I think that a pump that large is overkill, but that is just me. I also like to differentiate between FLOW and TURNOVER rates. I believe that you need a much lower TURNOVER rate than most people suggest. I also believe that you need (for SPS anyways) MORE FLOW than what most people suggest.
If you are going to build a manifold, you'll have some loss there. I'm not in a position to calculate that now, I'm off to a meeting. But, if you want, check out or search for Anthony Calfo's Manifold ideas. I believe Melev has some posted on his site too. Use them, their design and then calculate the pressure losses before you decide on a pump.
it looks like i will be getting a 120 gal. w/ 40 gal sump and probably going to run the sump a little over half way so like 25 gals extra. so with that making my total volume 145 (150 maybe). and i know you want to turn that volume over 10-15 times. making that 1500-2250 gph.
I agree with what Dave is saying about "turnover" vs "flow". Personally, I would suggest going with a lower turnover through your sump (3-5X is sufficient). And I would get the rest of the flow within the display. Your idea of a closed loop manifold is a great way to distribute flow into more areas of the tank, without blasting away from one powerhead output. However, I wouldn't recommend a spray bar...haven't heard too many good things about those.
If you use a closed loop manifold, you can plumb tubing and outlets across the top of your tank as well as down along the back of your tank and towards the bottom. Also, you'll have the advantage of not having all the powerheads IN the display, which some consider an eye-sore.
Here's a link that I think Dave might have been referring to: Goodbye Powerheads
my few comments in addition.
the Mag pumps are great for the price, but tend to be a bit lound, and the get real hot.
check out little giant pumps, quiet one pumps, and iwaki pumps.
these are what are used in the tanks where "people want the good stuff"
and as mentioned, dont worry about moving that much water from the return pump.. make it up in your flow (as opposed to turnover as dave mentioned)
and as far as over all flow, my minimum recommendation is 15x, preferably 20x.. 10x is a bit low IMO
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yea i never thought about that. i was thinking turnover instead of flow. i wasn't thinking of them as two seperate things. but i get what you guys are saying.
what i was thinking exactly was. having 2 return lines from the one pump. and then splitting those lines inside the tank. so basically having 4 returns on a 3000gph pump. which would be like 750gph in 4 directions. which would be like having 4 powerheads inside the tank.
would that be a good thing? or is that how you guys do yours?
cuz i would like to cut back on the powerheads and have no power heads at all if possible. i mean i can split the lines and use locklines to direct the flow and change the direction every now and again when needed. tell me what you think.
and i'm looking right now into the manifolds...
gwen i've decided that FOWLR won't be enough for me and i want to take the dive straight into reefing. starting with a few hardy corals of course. i like sps and i like lps. i still have to study up on species naming and the requirements. but i was thinking over a year of getting a few corals and then learning more on the way to keep what i want and actually deciding to go sps or lps or both (if that's possible).
Last edited by cheng21tang; 04-27-2006 at 06:04 AM.
i read the calfo site and saw the manifold. i think i might do that. but again he did it with a pump from the sump and ran 1 return and broke it off like 7 times with tee's. that's what i was thinking. i wonder that it would be unsightly to see pvc at the top of the tank? i'll try it out.
and i read that because mag pumps are magnetically driven it's ok to throttle it down but when you throttle down direct drive pumps it does damage to the pump. and wears it down (lifespan). just to let you guys know if you don't know.
i'll draw up a manifold type return and tell me what you guys think. i'll post it later when i have time to do it. then i'll figure out the pump to pick to run it. thanks
ok to void the other 2 post. when i thought i got it but i guess i didn't. but now i do.
turnover - volume entering and exiting tank
flow - gph in display only
so i guess instead of one big mag 36
i'll get 2 smaller pumps maybe 2x mag 12 and use one for return and use another one for a closed-loop/manifold (is manifold another word for closed-loop?) and get the flow i will need in the future.
what i was thinking exactly was. having 2 return lines from the one pump. and then splitting those lines inside the tank. so basically having 4 returns on a 3000gph pump. which would be like 750gph in 4 directions. which would be like having 4 powerheads inside the tank.
Yes, you could split the returns. In fact, it's a safer way to go, because if one of the pumps every goes out or if you need to service you, then you've still got the flow going. So, if you can afford to split up the return, then go for it.
BUT - you've still got ALL of your flow going through your sump, which I would still consider turnover. Even if you split up your return and direct it into the tank via a manifold, you've still got 15-20X water flow going through your sump. The biggest problem with such a high turnover is that your skimmer has less of a chance of pulling out all the yuckies out of the water if it's just whizzing by. By having a slower flow through the sump, you'll allow more of the water to come in contact with the skimmer, thus removing more impurities and proteins. Does that make sense?
Check out my tank thread. I've designed a manifold - not to say that it's necessarily the best design, but maybe it will help to see how you can design it. Typically, people (if they've got acrylic tanks) drill two holes towards the top part of the back wall (as you can see in my diagram). These holes and then connected to tubing and pumps that bring the water back into the aquarium over the top of down the back. I've designed mine to take OUT of the aquarium in two spots and then to deliver the water back in via a manifold. And then I've got my return lines going down the back wall in order to get more flow towards the bottom half of the tank.
If your goal is a more LPS/SPS tank- then go towards the "more flow" spectrum. You prolly want about 18-20 tanks per hour minumum with all your powerheads/pumps added up.
And always keep a backup pump just in case your main pump goes out since it sounds like you want to use one pump.
gwen
lighting wise i can't afford mh for a while. but i will probably start off with some VHO's. probably 4x96 watts. 2 full spec and 2 antinic. what do you guys recommend by BRAND??? any recommendation brand-wise would be great. i mean from your guys experience.
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