Maximize Pump Flow Rate With Larger Diameter Pipe? – 01/16/08
I was in touch with Danner Mfg. today regarding their Mag Drive Pumps and flow charts. They confirmed that their charts say that you must use minimum 1-1/2" hose to get maximum flow.
<<Yes, I have heard this about these pumps as well. Although, I do seem to recall some “unofficial” testing re that indicated the advantage to using the larger diameter piping on the output was marginal>>
Since many return lines are much less (AGA overflow kit has 3/4" for example), most aquarium users are getting a significantly reduced flow.
<<If using these pumps you mean…maybe so. Although the pipe diameter may play a small part, my own experience with these (most any brand) pumps is that the presence and number of bends/restrictions (elbows/tees) plays a much greater role in flow reduction>>
I'm using a Mag 7 submersed in my wet/dry in a 54 gallon reef tank.
<<This “size” pump is likely ideal (after headloss) for the drain on this tank>>
I was considering going up to a Mag 9.5 to increase flow, but according to them I could go significantly larger.
<<I disagree… Unless your plumbing configuration presents a “bunch” of back-pressure/headloss to the pump, I think you run the risk of overwhelming what is likely a 1” drain with even the Mag-9.5 pump>>
In the AGA brochure, it states that the built-in overflow can handle up to 600 GPH using a 2400 GPH rated pump at 5' of head.
<<Mmm, I’m not sure what the correlation to the 2400gph pump is here, as it is “way too much” for this tank’s overflow drain …which should in reality be limited to a return of no more than 300gph>>
So I think that means I could use a Mag 24 if my return line is 3/4" which it is.
<<Not even close… Though the Mag Drive is not a true “pressure-rated” pump, a Mag-24 will move a whole lot more water than your tank’s 1” drain can handle…even through ¾” pipe at 5’ of head. As mentioned, the return flow for this tank should be regulated to about “half” that stated in the kit (i.e. - 300gph), else you risk overfilling/overflowing the tank. You can try the Mag-9.5 if you want/truly think the return flow is that diminished with the Mag-7, but be sure to plumb a gate-valve on the output side of the pump to temper flow if needed. But, if you need to significantly increase water flow within the tank, you will have to turn to other means (powerheads, Tunze Stream pump, closed-loop…)>>
Are there any pumps out there that are rated accurately for aquarium use when using 3/4" return line?
<<All things being equal, a true pressure-rated pump like the Iwaki “RLT” line of pumps is a good choice/is likely what you seek here. But the Iwaki is an “external” pump…if you want a “submersible” with more “power” than the Mag Drive pumps; look in to the Ocean Runner line of pumps. In “my” experience, the OR pumps deliver more flow at a given height than a like-rated MD pump. I also consider the Ocean Runner pump to be more reliable than the Mag Drive (less prone to freeze-up or not “restarting” if the power goes off), and they run smoother/quieter>>
Let me know what you think.
<<You have my input>>
Mitch
<<Regards, EricR>>

Question Regarding Two-Pump Sump And Refugium Return Setup – 12/13/07
Hi,
<<Hello>>
I can't seem to find an answer to this question in your website and I'm wondering if you can help me.
<<I shall certainly try>>
I have a 110 gallon FOWLR with a wet/dry sump and an Eheim Hobby 1262 return pump (900gph) that is currently running.
<<Okay>>
I'm planning to add another sump just for refugium (live rocks and macro algae) and use my Mag-Drive (1200gph).
<<Mmm…>>
Would there be any problem if both sumps (with different pump speed) are running separately into the same tank??
<<Even though you have not provided any information re your plumbing scheme (Number/size of drains, how these vessels will be “fed” from the tank), I recommend you do NOT try this… Even if the drains are sized appropriately for the flow rates, you will have great difficulty/an impossible task keeping the flow regulated for the individual pumps (and before you ask…no…valves on the drain lines are not the answer). What is most likely to happen is the flow will equalize between the overflows causing one pump to starve and one pump to not keep up (overflow the vessel). Even if you use dissimilar drain diameters, the smaller will be overwhelmed and surge…with the resultant noise and bubbles. Nor is utilizing two pumps of the same flow/manufacture going to work as differences in head-pressure caused by subtle differences in plumbing, even differences in the rate of buildup of bio-film within the plumbing, will still keep the flow from being exactly the same between the two. Your best option is to plumb the refugium to gravity-drain in to the pump chamber of the sump (fed by one of the drains). And there’s no reason you can’t put both pumps here (the sump) if you wish to have the extra flow…assuming your drains can handle the total output, which for the two pumps you have listed I recommend three – 1/1/2” drains OR two – 2” drains …minimum…>>
Thank you in advance for your response.
Regards, Miguel
<<Happy to share Miguel… Do write back if what I have stated is not clear or you wish to discuss further. EricR>>

Overflow prevention, electrical kill switches    9/28/07
Crew-
<Craig>
Do any of you clever people know of an electrical approach to keep the power off to my return pump in case of a power outage?
<Mmm, there are a few... you can build or buy... I'd call on a licensed electrician here... as "the code" varies by State, country...>
I have a return pump that I do not want to restart in case of an outage.
<You are wise here... too much chance of more trouble... overheating, fire...>
I have done some searching re this subject but have only found generators, battery backups to take over for a loss of power. I am looking for a solution that would keep the power from coming back on to the pump in the event that power is lost.
<There are such switches...>
Having staged several "drills" to test my overflow, there is no way I can be assured the overflow will restart and keep up with the return pump if power is lost. Adding additional draining capacity is not an option at this stage.
Thanks for your input, contributions.
Craig
<Mmm, am wont to state much for fear of liability... Again, there are simple devices to do what you want. Perhaps even available "off the shelf" at large-box hardware stores... Bob Fenner>

Pump Mounting/Damping Vibration – 09/26/07
Again after searching through the web I resort to this wonderful wealth of knowledge.
<<We’re pleased you think so>>
I have been looking for the best way to mount two Sequence Darts underneath my tank. Oh by the way, I'm assuming it's better to have a pump pushing the water rather than pulling it, am I correct?
<<Oh yes! The pumps need to be flooded/gravity fed/positioned below the tank>>
I had thought about mounting the pumps on rubber mats, but I'm not sure how to fix everything together.
<<...?>>
Obviously if it’s screwed in anyway to the floor it will transfer the noise, and the rubber pad will be for not.
<<Ahh...yes, you are correct. But there’s no need to “secure” the pumps so... Simply let them “rest” on the rubber pads>>
The rubber can be glued to the floor, but I’m still stumped how to mount the pump to the rubber in a way that it can removed easily for routine service/cleaning.
<<As just stated>>
What solutions do most people use? These pumps will be mounted in-line and not submerged.
<<I like to use segments of the rubber flooring used in workshops to lessen back fatigue from standing on a concrete floor...but you can use just about any material that will dampen vibration...including simple computer mouse pads>>
Once again, I am grateful for your experience.
Cheers,
Olly
<<Happy to share, Olly. EricR>>