flow and plumbing for 50g

[treesprite]

I bought a used 50g tank, which has a 36x18 footprint. I need to figure out flow and plumbing, but I have never had a tank with that footprint to play with.

 

It has only one hole, drilled on the back, which I think is for a 1.5" bulkhead. I am not planning to drill any other hole in it. The overflow, which had been removed and would need re-attaching, is really tiny, so I may (probably will) get or make setting else that is longer.

 

I will have the 3/4th" Sea Swirl which was listed on the for sale board. I have never had one of those. The max rated outflow for it is 850gph. Is the 3/4" SS with a max output of 850gph enough for this tank, without adding another flow source, or will I need to combine it with something else? (Reminder, tank is a 50g that is 36" long and 18" wide, and will be mixed reef).

 

Any ideas for the plumbing and overflow that don't involve drilling?

 

I have a somewhat wide assortment of little tanks of various sizes and shapes, so can play with ideas for add-ons like sump, fuge, ATS, or whatever.

[madweazl]

How long is the overflow? I run a 12" overflow (only 1" wide) on a 48" long tank and it works well. Something else to consider is that if you run the SS at max, you're also pushing 17x flow through the sump which is generally higher than any recommendation I've seen (though I'm not sure I believe higher flow brings with it, problems). In regard to DT flow, that puts you below 20x turnover rate so I guess the more appropriate question is, what are you planning on keeping in there? If the SS is at one end of the tank, it's easy enough to drop a powerhead/wavemaker on the other end to supplement if need be. Do you know how max flow rate for the overflow box you currently have? 

[treesprite]

I have a same-size overflow box in a 20H, so I know it doesn't handle much flow, probably only 500gph. It is probably only 5" long. I had coast-to-coast overflows in both of the 75s I had, so I am used to having the benefits of a long overflow. This tank is 36" long, so I really feel like minimum OF length should be 12".

 

The way I usually set up sumps and fuges, high flow in the sump hasn't been a problem. However, I don't know how I will set this system up. I'm probably not going to use as proportinally big of a sump as I usually use, which automatically will prevent me from using a big return.

 

I thought about doing an over the back loop like the one on Melev's website, and using the SS for that return (except that his uses SCWDs). It would solve the problem of high flow in the sump, but would put a long piece of pipe in the display (intake for loop he has is a long pipe with lots of holes). I could use black PVC. That would also allow me to have a second loop return, though I would want it lower in the tank, which would again put a piece of pipe in the display. The pipes would be partially hidden by rock, and if I use black PVC and have the back of the tank painted black, that will help to hide them. If I did the loop, I would be able to stick with the tiny OF though, so that would maybe make having the piece of pipe in the tank less of an issue.

 

I may end up not having a traditional refugium, but maybe an ATS made out of a 16H tank. The tank is tall and narrow. It is drilled on the end, so I can plumb through that hole, a pipe with holes or a slot all along it. There would be a few inches of water in the bottom and a small return pump. I'm not sure if I would have the ATS return go to the sump or the tank... that is another consideration for flow if it goes back to the tank. I wouldn't want to risk bits of algae going in the tank, though. I have been wanting to do an ATS with this 16H for a long time. Space is an issue, so I will figure it out when I actually have the tank sitting on the stand (the tank is in the car, and I'm not picking up the stand until Monday, when I'll have a bigger vehicle).

Edited October 24, 2017 by treesprite

[treesprite]

I just noticed that the overflow is a Glass Holes overflow which is only 6" long, and attaches via the bulkhead.

 

I kind of want an inside/outside overflow.

Edited October 24, 2017 by treesprite

[madweazl]

Modular Marine is making them again. 

[treesprite]

Modular Marine is making them again.

I literally just saw their response to me about making one custom for me. It costs just an extra $15 on top of the price of the overflow. They are great looking in the pictures, but I have never seen one in person. Does anyone here have one, who could give me some feedback about them?

[madweazl]

I have one on my 75g that works great.

 

Internal (roughly 12" x 1.25")

 

External

[treesprite]

Thanks for the pictures.

 

If I get one, it would probably be that middle sized one, but only have one hole that is for 1.5" bulkhead, instead of 2x 1". I really want a longer overflow, but I'm already debating how much I'm willing to spend. I need to research other options still, but I like a lot of the features of these ones. I didn't know about this company before now.

[madweazl]

Single 1.5" will support plenty of flow and those guys will make you a custom one. They made some changes to the one above and I don't think it cost anything (if they did it was minimal). I think it was around $135. 

 

Edit: drilling holes is easy too. 

Edited October 25, 2017 by madweazl

[treesprite]

I dont want to drill this tank... I do, but am not going to do it. I have done a lot of drilling. I drill practically everything. My 20L sump has 2 drilled in it, both 20H tanks are drilled, the 16 bow and 16H are both drilled, and I drilled past tanks that I had. I'm trying to make things more simple, and trying to avoid physical pain which lasts for at least a couple days (I have an improperly healed past distal radius fracture).

[treesprite]

I still haven't made a decision on the Modular Marine overflow, but have price quotes for custom options. Right now the tank is only filled to the bottom of the tiny Glass Holes overflow that is in it (there is only sand and some rock in there, no livestock).

 

I forgot to go pick up the Sea Swirl I bought from Matt. How could I forget something like that?

 

I'm still thinking of making an over-the-back CL. The one on Melev's website uses a piece of pipe full of holes to take in the water. I don't plan on buying a SCWD, though. I was thinking about just using the loop to put flow from the bottom of the tank up, possibly through the rockwork, since the Sea Swirl should do a good job for the flow in the upper half of the tank. I hate powerheads, so am trying to avoid them.

 

Has anyone here, on WAMAS, used an over the back CL?

Edited November 12, 2017 by treesprite

[Origami]

Has anyone here, on WAMAS, used an over the back CL?

Not me. However, one old member, Marcia (aka fishwife) and her husband used an over the back closed loop. You may be able to find their old build thread if you're interested in it.

[treesprite]

Thanks, Tom.

 

It took me forever to drill a bunch of holes in a piece of 1" pipe for the CL intake last night. The only pump immediately available (without digging around junk or taking apart plumbing that is in use) to test it, was a submersible only pump that is 800 gph, so I put the stuff together in the 2/3rds filled tank with the pump in the tank. The output from the pump is only half inch, so the manifold is all half inch.

 

The manifold (not glued together for testing/experimenting phase), is a bottom-only one, with 2 outputs in the back of tank and 2 in the front of the tank (is 36"x18"). I have the back outputs pointing more upward, and the fronts lower, more angled down not so noticeable (the back ones will be behind rocks). I didn't connect it all the way around, because I don't want a piece of pipe across the front (though it would be under sand; might need to add some more sand). However, there is higher flow from the outputs closest to the input from the pump, so I am wondering, would connecting the pipes all the way around balance that flow rate out between outputs? (I don't plan on buying a SCWD or whatever, due to budget, but that may change, depending on other cost factors).

 

I can see the flow from the backs mixing together on the surface of the water, and the fronts are strong enough to blow the sand out of my hand (or make holes in the bottom sand if angled down too much); I can't see that flow on the surface because they are angled low, and the higher flow from the backs might just be hiding the more gentle flow from the fronts). So, I am wondering if the pump actually is big enough for a bottom-only CL, such that when combined with the Sea Swirl up top (can handle 850 gph), I would be able to avoid powerheads in the tank without having to use a bigger CL pump (this submersible one is small enough to go in the sump) (need enough flow flow/movement for sps and lps).

Edited November 14, 2017 by treesprite

[treesprite]

Everything is still kind of up in the air. Maybe I am making too big of a deal out of having the little overflow, when I should be using the resources on having good in tank flow and movement which does not involve the water going to and from the sump. I will need new lights at some point also, since I'm temporarily going to be using a 48" fixture due to budget.

[treesprite]

I just ordered a SCWD from Marine Depot. I thought they were a lot more expensive, but it was only $31 for the 3/4th" with free shipping (I paid for upgraded shipping).

 

So, I am going to scrap my test manifold and make separate sections to work with the SCWD.

[treesprite]

So, I am having second thoughts about using a SCWD on the CL. Do I really need switching current on a bottom-only CL? Maybe it would make more sense to use it on the sump return, even though I will be using a Sea Swirl, because the Sea Swirl by itself would have me not diverting flow to have anything coming from the opposite side of the tank. If I don't use it on the CL, I will just change the pipe diameter on the front center section of the CL manifold.

[madweazl]

So, I am having second thoughts about using a SCWD on the CL. Do I really need switching current on a bottom-only CL? Maybe it would make more sense to use it on the sump return, even though I will be using a Sea Swirl, because the Sea Swirl by itself would have me not diverting flow to have anything coming from the opposite side of the tank. If I don't use it on the CL, I will just change the pipe diameter on the front center section of the CL manifold.

Doesn't that kind of defeat the purpose of the closed loop though? 

[treesprite]

Maybe. I am probably over-thinking things.

Edited November 22, 2017 by treesprite

[treesprite]

I ordered a Mag 9.5 for the CL, and am wondering if I should dig out the manifold and make pipes bigger. The pump has a 3/4" connection, but someone somewhere said the pipe should be bigger for the mag pumps. Anyone have any feedback on that?

 

Since DrsF&S gave me a free $50 gift certificate for ordering at the right time, I went back on there today and used it to buy a Quiet One 4000 for return pump (I have a QO 6000 which I have used for a return for several years, but I would have had to dial it down. Right now it is in the 20L sump for just a 20g DT tank with just a tiny overflow with just one 3/4" bulkhead, so it is dialed down to practically nothing.

 

DrsF&S gave me another free gift certificate (for $25 though, not $50), when I bought the QO pump, so now I need to buy something else. It is after midnight, so I think their big sale and free gift certificates deal is over.

[Origami]

Go with the largest plumbing you can tolerate, Forrest. It reduces dynamic (friction) losses and gives you more flow at the tank. It's also easier on the pump. Use an adapter at the bottom to move to the larger pipe as early as possible, and delay reducing until as late as possible. 

[treesprite]

Do you mean for both CL and sump return pumps?

 

I haven't done any of the external plumbing at all yet, just bought the pieces.

 

The Mag pump has a 3/4" connection, so I got fittings to go up to 1". Should I go all the way up to 1.5 even though it will get reduced to 3/4" in a couple inches to go into a 3/4" SCWD?

 

The QO 4000 I think has a 1" connection, like the 6000. I have always just been using 1" pipe for the 6000, but have always had to dial it down anyway, so it didn't matter.

 

I am going to have to sit the CL pump lower than planned to change pipe size, to have space for the extra pieces of plumbing, because the SCWD takes up so much vertical space.

[Origami]

Yes, both. Anytime there's motion through pipes there's friction. How long is the run from the pump to the SCWD? Are there elbows along the way? The SCWD is going to cause some loss, too. Closed loops have an advantage as there's little head loss from lifting water. However, there will be friction losses and losses due to restriction. 

 

The output of the Mag is specified at 975 gallons per hour with 0' of head loss and no plumbing. The SCWD will knock 10% off of that, or nearly 100 gallons per hour. That's like about 4 feet of additional head in a normal application for that pump. So, using that as a "vertical lift" figure on RC's head loss calculator and assuming a simple straight run upward, one elbow to get into the tank, no horizontal runs (yes, I know this isn't your plan - esp. with the SCWD teeing off the way it does) and further modeling your 2x actual vertical lift (assumed to be 5') to account only for friction losses of the intake and pressure sides, you're looking at

 

• A max of 597 gph using 3/4 inch runs the whole way
• A max of 725 gph using 1 inch runs
• 787 gph for 1-1/4 inch runs
• 801 gph for 1-1/2 inch runs

So, you can see the declining returns but you can also see the benefit in flow of using larger plumbing. The actual performance may be a little worse off for the larger plumbing because of the final stage where you neck down to get into the tank.

 

The bottom line is that head pressure reduces flow, which often leads us to select bigger pumps that cost more to operate over the course of a year. Operating 24/7, one Watt less of power consumed puts more than a dollar back in your pocket over the course of a year. Over time, thoughtful consideration of plumbing can pay for the pump in the savings it reaps over a less efficient setup.

 

In your application, where you've already got the Mag 9.5, I'd probably settle in on using 1" or possibly 1-1/4" pipe.

[treesprite]

Thanks, Tom. The reason I joined WAMAS was to have other people do the math for me.

[Origami]

Thanks, Tom. The reason I joined WAMAS was to have other people do the math for me.

 

[D805]

Yes, both. Anytime there's motion through pipes there's friction. How long is the run from the pump to the SCWD? Are there elbows along the way? The SCWD is going to cause some loss, too. Closed loops have an advantage as there's little head loss from lifting water. However, there will be friction losses and losses due to restriction. 

 

The output of the Mag is specified at 975 gallons per hour with 0' of head loss and no plumbing. The SCWD will knock 10% off of that, or nearly 100 gallons per hour. That's like about 4 feet of additional head in a normal application for that pump. So, using that as a "vertical lift" figure on RC's head loss calculator and assuming a simple straight run upward, one elbow to get into the tank, no horizontal runs (yes, I know this isn't your plan - esp. with the SCWD teeing off the way it does) and further modeling your 2x actual vertical lift (assumed to be 5') to account only for friction losses of the intake and pressure sides, you're looking at

 

• A max of 597 gph using 3/4 inch runs the whole way
• A max of 725 gph using 1 inch runs
• 787 gph for 1-1/4 inch runs
• 801 gph for 1-1/2 inch runs

So, you can see the declining returns but you can also see the benefit in flow of using larger plumbing. The actual performance may be a little worse off for the larger plumbing because of the final stage where you neck down to get into the tank.

 

The bottom line is that head pressure reduces flow, which often leads us to select bigger pumps that cost more to operate over the course of a year. Operating 24/7, one Watt less of power consumed puts more than a dollar back in your pocket over the course of a year. Over time, thoughtful consideration of plumbing can pay for the pump in the savings it reaps over a less efficient setup.

 

In your application, where you've already got the Mag 9.5, I'd probably settle in on using 1" or possibly 1-1/4" pipe.

Great information. I was just thinking about this same thing yesterday, as the pump I bought comes with a 1" and 1-1/4" union.