Basement Sump / Pump question

[inetjnky]

I'm working out my head height and the pump for my upcoming basement sump build. I'll have a frag tank in the same room in the basement with a 185g display on the floor above. Rough estimate on head height to the 2nd floor tank is between 16 to 20ft. I'm looking at the Iwaki pressure rated pumps, but what I'm trying to figure out is, I plan to T off the return a few feet above the pump and run to my frag tank with a valve right after that section of the T to decrease the flow to the frag tank. My question is, how much impact with this have on the pump sizing and should I size bigger? I'm trying to size for 3-5x flow through the main display. I've been looking at the 55RLT but am wondering if I should bump it up to the 70RLT to account for any decrease from directing flow to the frag tank?

 

[dankaqua]

The usual method is to subtract one foot of head per fitting (e.g. elbow), but in your case the tee is actually directing water to a "different system". With a valve on the frag tank, you can control the amount of flow it gets. So just subtract the flow per hour going to the frag tank from the total calculated flow going to the display tank.

Using the below graph as an example (looks like the "55RT" is not the same as a "55RLT" but it's what popped up)

So my late-evening math for the 55RT looks like:

@16' - 11gpm -- 60*11= 660gph
@20' - 9gpm -- 60*9 = 540gph

So with your parameters of 3-5 times turnover, you'd need:

3x turn over 555gph
5x turn over 925gph

So not including the frag tank or any fittings, the 55RT gets you just over 3x turn over.

Add in the fittings, and the 3x turn over is not doable with that pump, and you still haven't calculated your frag tank into the mix.

Sorry for the poor example, but hopefully it can be a point of reference.

 

[inetjnky]

The usual method is to subtract one foot of head per fitting (e.g. elbow), but in your case the tee is actually directing water to a "different system". With a valve on the frag tank, you can control the amount of flow it gets. So just subtract the flow per hour going to the frag tank from the total calculated flow going to the display tank.

Using the below graph as an example (looks like the "55RT" is not the same as a "55RLT" but it's what popped up)

So my late-evening math for the 55RT looks like:

@16' - 11gpm -- 60*11= 660gph
@20' - 9gpm -- 60*9 = 540gph

So with your parameters of 3-5 times turnover, you'd need:

3x turn over 555gph
5x turn over 925gph

So not including the frag tank or any fittings, the 55RT gets you just over 3x turn over.

Add in the fittings, and the 3x turn over is not doable with that pump, and you still haven't calculated your frag tank into the mix.

Sorry for the poor example, but hopefully it can be a point of reference.

Thanks for the feedback. I was adjusting to 20ft for the fittings. However I’m in agreement that I may want to bump up to the 70 or even 100 to get within my desired range. What I’m trying to not do is over power and have to throttle the main display down. I was planning on placing a gate valve directly after the T. The other option was to run a second external and put the frag tank on its own pump. Not sure i want to do that though.

 

[ca1ore]

Something to consider ….. why not feed the frag tank from the display drain rather than 'stealing' from the return pump; take advantage of all that free gravity. I have a similar setup and that is what I do. In fact, I have my siphon split three ways - one feeds the frag tank, a second feeds the ATS and the remainder feeds the UV. Saves me three pumps …. woo hoo

 

[inetjnky]

Something to consider ….. why not feed the frag tank from the display drain rather than 'stealing' from the return pump; take advantage of all that free gravity. I have a similar setup and that is what I do. In fact, I have my siphon split three ways - one feeds the frag tank, a second feeds the ATS and the remainder feeds the UV. Saves me three pumps …. woo hoo

Thank you for the recommendation. I hadn’t thought about that actually. I plan on feeding my refugium with 1/4 of the drain water but never considered the frag tank too... hrmmm.... only benefit to two pumps is if I need to work on the display upstairs I could keep the frag system running uninterrupted.