Flow/Stream question

[Submerged]

Couple of q's about flow rates in general and the Tunze stream pumps in particular.

Am in the process of setting up a 125 gal (72" long) tank. Instead of standard overflows, I am using 3 x 1.5 drains (drilled through the back of tank (~3-4" from the top). The drains empty via pvc through my floor and into a temporary sump (100 gal rubbermaid stock tank) in my basement (~10 ft drop). I'm having a custom sump (~115 gal) and separate fuge (~30 gal) made. I bought an Iwaki MD100RT pump (~1800 gph) to handle return flow from the sump. Currently, there's nothing in the tank besides H2O (and several thousand microbubbles when I run the pump...as the temporary sump is not propperly baffled).

This is an artists rendition of how my drains empty into the sump:

You might imagine this is a bit loud...

I also have a closed loop system (1 outlet, 2 inlets; bulkheads drilled directly into the tank) which was running on an Iwaki MD40RT (~700 gph). The inlets attach to spray bars, and I had plumbed in a SCWD. The SCWD makes my tank sound like a dishwasher and produces whistling and cavitation (but no microbubbles) as the turbine turns.

Here's what I was thinking of doing:

1. Removing the SCWD.
2. Keeping the closed loop running as continuous flow through the spray bars.
3. Downsizing the return pump on my sump (have questions about this below).
4. Adding a Tunze 6000 stream pump (or 2??) and multicontroller to compensate for flow loss resulting from downsizing my return pump and to replace the wavemaking properties of the dysfunctional SCWD.
5. Taking out a loan to buy groceries, corals, etc.

Here's my main question:

How much flow do I need/want through my sump? Are there guidelines on this? Is it ok to subtract flow through the sump and replace it with internal-tank flow?

What would be a reasonable pump to downsize to? I was thinking of the Iwaki MD55 (1080 gph at 4' head...more like 800 gph with my plumbing setup).

Thoughts on how I might use the Stream(s)? Was planning to use sand as a substrate...

Thanks in advance.

 

[rvitko]

:lol:

I would do this- forget the closed loop. Go to the mid size GRI pump for a return- they are quieter and use half the electricity of Iwaki and are very easy to service since they have a wormband that holds the face on instead of the multiple bolts. They do cost more but they use a great motor (Fasco) and just are really well made American pumps. You will only need 4-5 times tank volume in turnover. Then, add two 6000's and a multicontroller and you will have plenty of flow. I don't know where you live but the energy savings is going to be quiet a bit. You presently use 565 watts to pump about 2800 gph. My solution will use 168 watts to pump 4500 gph.

 

[Submerged]

I would do this- forget the closed loop. Go to the mid size GRI pump for a return- they are quieter and use half the electricity of Iwaki and are very easy to service since they have a wormband that holds the face on instead of the multiple bolts.

Thanks Roger,

Ok- so this one seems to be their "middle one" (GRI1458):
$249.99
1020 gph
115V
50/60Hz
2.8/2.4A

vs. this one:

IWAKI MD55RLT
$259.99
1080 gph
115 V
1.6A

I rode the short bus to electrical school, so I'm sure I'm missing something about power usage between the two...

Any reason not to use the closed loop for additional circulation? Or is it just overkill? It's hard-plumbed into the tank via drilled bulkheads...I'd have to cap them or just leave the pump off otherwise.

This would permit something like:

700 gph closed loop + 800 gph return pump + (2 x 1850 gph Tunze Stream 6000)

5200 gph on 270 gal total volume (125 tank, 115 sump, 30 fuge)...not quite 20x turnover (but most of the turnover occurs within the 125 tank...this is where I get confused about how much flow I need).

TIA

 

[rvitko]

In AC motors and heaters as well as ballasted lamps it is what we term and inductive load- it takes as much power as it needs and this fluctuates. Watts is A * V * PF- the PF or power factor is what you are missing and the two pumps you list are close like 180 for the Iwaki and 130 for the GRI. Champion Lighting has a chart and this is the source I use.

The closed loop is overkill. It isn't the one time expenses that kill a hobby, it is the long term monthly expenses like electricity. I miser by buying quality once and saving as much electricity as possible in every aspect of my house.