External pump

[Viperdoug]

I am trying to figure out which model of Iwaki pump to use on a new frag tank. The total water volume between the display and sump is 160 gallons. THe sump will sit directly beneath the display with a total difference of about 3' from the pump to the display. Hopefully someone can help me.
Thanks!

 

[tinctorus]

Does it have to be an Iwaki pump?
Reason I ask is I have an Iwaki pump on my 65 gallon and have used Iwaki pumps on a number of peoples tanks and can say without a doubt the new Reeflo Blohole series pumps are WAY WAY WAY better and priced better for what you get as well, Also they have 3 different modes for different GPH outputs that can be adjusted with the turn of a dial

 

[Viperdoug]

Actually, I was more interested in the Reeflo as I hear they are quieter. Which Reeflo would you recommend?

 

[Jlobes]

Not sure if its still happening, but there was a promotional pricing for the BH2700. they were like 169 shipped. havent installed mine yet, but they are great looking pumps with great looking specs.

As for a recommendation, How much flow you looking for and how much head do you have??

 

[Viperdoug]

How is head calculated? Is it the total height difference? If so about 3'. Or is it the total length of the pipe it runs through? If that then about 11-12'. I will be keeping mostly LPS and ricordeas

 

[Chompers]

Head is only the vertical heigth. The horizontal run is so minimal that it can be neglected from any calculations.

 

[Viperdoug]

Ok, so I have about 3.5' of height. Will the Reeflo BH1450 be sufficient if I add a second 50 gallong frag tank later? I am not finding the BH2700 online.

 

[tinctorus]

Ok, so I have about 3.5' of height. Will the Reeflo BH1450 be sufficient if I add a second 50 gallong frag tank later? I am not finding the BH2700 online.

I responded to your PM, The 1450 should be MORE than enough, however you still could go with the BH2700 and turn it to the lowest setting, that way if you upgrade tanks you dont have to upgrade pumps...I dont however kno the price difference between the 1450 and the 2700

 

[OurReef]

Every 90 counts as 1' of head from what I've been told and read. Factor that in too. Buy big and tune it down to what you need. Gate valves and bi passes can help you fine tune the water flow.

I run a 4 port manifold, three 3/4" hoses running to sea swirls and one 1" hose that runs directly back into the sump.

 

[Chompers]

Every 90 counts as 1' of head

No, actually that is just a myth perpetuated by people that don't know the math. There was a time that I did know the math (still do, just don't want to), and at the flow rates and pressures we use, it takes several hundred 90 degree fittings to equal one foot of head.

 

[AZDesertRat]

Thats not true. Fittings do contribute to head loss and must be considered when calculating a pump size. I think you do need to get your math books out again. At lower flows and/or with increased size plumbing it does not have as much effect but it does add losses. Same with longer than normal horizontal runs, all pipe has a resistance to flow or C factor that must be accounted for. Use one of the calculators on all the reef sites and pay attention to what it tells you. Also never take one persons word for anything, no matter how many posts they have or who they are. Its not a myth!

 

[Chompers]

No, actually that is just a myth perpetuated by people that don't know the math.

Btw, proof of this is that six fittings (not hard to do) would completely choke down any smaller pumps but they still work fine at tank height.

 

[Chompers]

And yes, it is a myth.

 

[AZDesertRat]

Again consider the source. Check around for more knowledgable answers. It does have an effect, otherwise the calculators would not be there. Talk to a pump manufacturer if you want proof.

 

[Chompers]

Btw, proof of this is that six fittings (not hard to do) would completely choke down any smaller pumps but they still work fine at tank height.

Nope, worded all wrong... Smaller pumps that don't work at six feet of head will run fine with six 90 degree fittings at pump height. If the theory held true, the pump would not flow (yet it does not flow at six vertical feet).

 

[Chompers]

Talk to an engineer that can do the math. A lot of the calculators are wrong. They are not based on Bernolli's equation(s), but rather are based on a conservative value that was derived for pumps that are not used in the aquarium trade. The plastic pumps that we use are low flow/ low pressure. Most industrial pumps are high flow/high head. At extreme flow rates, the resistance in a 90 degree fitting sky rockets. At the flow rates that we use, the resistance is minimal.

Consider the source.

 

[AZDesertRat]

I rebuild, install and operate pumping systems as a profession and have done so for over 37 years. Hydraulics don't lie. I think I have a little more knowledge and experience than you do without even asking what you do or what your experience may be. If we were talking about pumps capable of 125 psi or hundreds of feet of head it would be different. We are talking about pumps that the head is measured in inches, or at most 10-12 feet. You can hold your finger over the discharge and completely stop the flow. Fittings, pipe size and length do make a difference. You aren't BSing me, I know better as does anyone else here.