Calfo Overflow & Closed Loop & Return Manifold

[captbunzo]

Ok. I have mentioned here that I am helping my sister setup a 90G tank in here office. Well - long story short, the tank is NOT reef ready like we were told this to be. However, in light of the extensive/obsessive reading I have been doing in this forum recently, I think this might be a good thing.

So, here is the basic plan:

1. Build a Calfo Overflow to deliver water to the sump/skimmer at a rate of approximately 800 GPH.

2. Build a Closed Loop and return water manifold driven by a Mag 24 pump that has already been purchased.

Now, there are some things I need to figure out in relation to setting this all up.

Calfo Overflow Questions

1. Minimum Length of Horizontal Overflow

I read in one of the horizontal overflow threads about Anthony's triangle shapped overflow box in the back corner of one of his tanks. I was (sort of) under the impression that the rule pretty much was: The Longer the Better! I assume that in reality, there is a minimum and a maximum bound on the length of horizontal overflow that will be effective. I also assume that the MAX is larger then the length of the tank, so it is inconsequential.

So, overflow question is: What is the minimum effective length for the horizontal overflow I build into this tank?

2. To drill or not to drill, for that is the question?

I have to get water out of the horizontal overflow and into the sump. As far as I understand, the two ways to do this is via either siphon, or drilling holes in the back of the tank. I understand that the drilled option is better, as far as reliability and (probably) throughput is concerned.

Now, when I put my 29G tank together I DID actually use a dremel to drill a hole and cut a horizontal overflow of sorts in the 1/4" glass. So I feel like I can probably pull off repeating this trick on my sisters tank. However, there is always the chance that disaster will strike. However, however, I am really pretty confident that I can pull it off.

The question is, should I just drill the tank? Or is there an effective method for siphoning the water out that will both give us the appropriate amount of flow and be reliable.

(Read: We REALLY don't want to flood her doctor's office...)

And, btw, if drilling is the best choice, I am hoping that I can get away with a single, larger bulkhead. This could have been a seperate question, but, er.....

3. Recommended pump for sump return?

We have a Mag 24 pump that we had acquired at a good deal from someone. That pump was GOING to be the return pump. However, I have realized that we don't really want/need 2000 GPH to be coursing through the sump. And I also figure that the Mag 24 will be a pretty decent choice for our closed loop.

Ok, we need another pump, then. I would really rather run this submerged in the sump. So I have been looking at either a Mag 9.5 or a Mag 12. At 5 ft head pressure, they are supposed to get 750 and 1120 GPH, respectively. I assume that this number would have to be dropped slightly to account for static pressure loss (pipe elbows, friction, etc).

So, the question is, which of this two pumps do you recommend? Or, do you have another pump that you would suggest instead?

Closed Loop & Return Manifold Questions

1. Placement of closed loop pump

Ok. In that this tank is not drilled, AND that I would like to drill as few POSSIBLE holes in it, I would like to submerge the Closed Loop pump directly in the tank. Of course, I don't want to kill any fish, etc.

Another factor is that I will get better pumping action of the pump is elevated off the bottom of the tank, somewhere closer to the return manifold. However, with it pulling in water near the bottom of the tank, I could see that having the potention for better flow.

So, the question is, with the parameters I have described above, what recommendations would you have for placing the pump, protecting fish, etc.

I HAVE, btw, read about the gutter guard suggestion. I am not sure I completely understood it, but I did read it...

2. Closed Loop Pump

Is the Mag 24 a perfectly acceptable pump for our closed loop? I would guess that it would be fine, especially "for now", upgrading later if we really wanted/needed to.

Is that fine?

3. Clear PVC piping

There is a part of me that wants to use clear PVC piping for anything inside the tank relating to the closed loop and return water manifold. While I know it is more expesive, I thought it might be nice to have things hidden better. Besides, it would give the opportunity to see what's inside, in case clogs or anything ever occurs?

Is there any bit of that that makes sense, or should we just use normal PVC piping?

Done...

Well, that's it for now. I will most likely have more questions later and will definately post pics and more details as the project progresses.

Thank you for your time and energy!

[A\/enger]

I wouldnt use clear pipe just for the fact that algae will grow inside the pipe. Stck with regular white or order/find black IMO.

[captbunzo]

Thank you for your input about the clear pipe. Sounds like some good reasoning indeed.

Note to all. I REALLY need some help with the rest of my questions. She is going to want to get going with this tank and I want to make sure I have the best answers & solutions when she gets around to asking.

[bvoss]

I'll add some more comments while Anthony is out.

There is no good alternative to drilling and at least 2 holes should be used. The cost of another hole and bulkhead is very small compared to the other things you will be putting in the tank. The extra outlet will give you insurance that you will not have a flood in the event a fish or snail finds their way over the overflow. Always use drains that are rated for at least double your max return flow. Drains running near max are noisy and trouble-prone. I would go with 2 1 1/2" drains just because there isn't much benefit to going any smaller.

I have done the dremel thing in 1/4" glass and it is easy. It might be a real pain with the thicker glass used on the 90 gal. It might be worth your time finding a glass shop that would drill them for you.



Do I understand you plan to actually put the Mag24 in the display tank? Normally you would drill another hole and keep it external. You have to clean Mags occasionally and hauling them out of the tank would be a real pain. An 1 1/2" inlet (maybe 2") would be appropriate for a Mag 24. Be carful not to restrict the suction side of the pump.

The Mag 24 is a good pump for a closed loop since it is not pressure-rated. It will move a lot of water. Pumps in closed loops do not have to pump against atmospheric pressure - only plumbing friction. Placement of your closed-loop pump will not impact performance the way placement if a return pump will.

A Mak4 is a good reliable affordable pump for a return. It might be a little noisy if the cabinet is not enclosed. A Mag 12 is OK if you stay with submersibles.


I hope that is helpful

Bill

[captbunzo]

Thank you for your post! Your input definately helped. Based on these, I have furthered my plans. Here is where things stand now...

There is no good alternative to drilling and at least 2 holes should be used.

Okie dokie. I got permission tonight to just get the tank "reef ready" and then bring it by her office. With that in mind, and with my prior experience in drilling a tank, I'll go for that plan. It may take a while, but with patience and plenty of water, this should work fine.

To Drill

I can go ahead and drill 2 holes along the order of 1.5 - 2 inches in size. One question added here - would there be any reason to drill 3 holes that would be significant enough to go through the pain (and risk) of drilling another hole?

Do I understand you plan to actually put the Mag24 in the display tank? Normally you would drill another hole and keep it external.

Well, that WAS the plan. However, I have a NEW PLAN NOW!!!

New Plan for the Mag 24

I am going to use the Mag 24 (along with a gate valve) in the sump as the return pump. It'll Tee off some flow from the sump return through the refugium to tumble some chaeto.

I was thinking this based on both recommendations I have found to NOT run a Mag 24 inline (only submerged) and (more importantly) that a mag 24 run inline would be very loud.

Plan for a Closed Loop

Pump and Manifold

And to feed the closed loop, I am just going to get her to buy another pump. After some research this evening, I am thinking about getting a Sequence ReeFlo Dart Pump. Another option would be for one of the Sequence 750 or 1000 Series Pumps. Hold your thoughts on these pumps for a moment...

Ok. This is a 90G tank. For the return manifold, I was going to aim at 8 return nozzles (1 nozzle per 10 Gallons, cheating by subtracting 1). These will be fed from a combination of 1.5, 1.25, and 1 inch piping. So, with a 400-500 GPH flow per nozzle, that would be 3200 - 4000 GPH through the closed loop pump.

So, with those parameters for the closed loop flow requirements, which of the above suggested Sequence pumps would you recommend? And, if you can recommend another reasonably priced pumps, that would fine as well.

Plumbing Considerations

Ok. Now the retun pipe for ALL of the above pipes are 1.5 inches in diameter. So, my plan is to take that 1.5 inch straight up into a 1.5 inch T at the top back of the tank. The pump will be somehow mounted behind the tank so that the distance of water flow can be kept down as much as possible.

Out of that T, I'll then reduce to 1.25 inchs. And then at the back corners of the tank, I'll reduce to 1 inch in size. I came up with that plan as a way to keep as much of the flow as possible from the pipe.

Also, to keep flow up, I was thinking I would use Long Sweep 90s whereever possible.

Horizontal Overflow Idea

I had a wacky idea today concerning how to build the horizontal overflow. That idea started with taking a piece of black acrylic about 6 inches tall by 60 inches long. Then I'll heat that acrylic and make it wavey of sorts.

And I'll take a similar piece of acrylic and cut it to fit with that wave, making a 1-2 inch overlap to mount those ever-popular encrusing corals.

And that whole creating will be sized just right to run the entire length of the back of the tank. Or, if Anthony tells me it isn't necessary, that might be modified to extend only part way across that back of the tank.

So, anyhow, what do you all think of these ideas? Please respond and let me know where I am on and off with these plans.

Thank you for your time and energy...

[bvoss]

I don't think you need a third hole for the overflow. Keep your flow through the sump down to around 1,000gph or less. Then a single 1.5" drain will be able to carry the load if the other one gets plugged or restricted. In normal circumstances you will be running at 1/2 the drain's rated capacity and that should keep things quiet and steady.

I do think you will need a third hole in you tank for a closed-loop You can rig up a system that will allow a closed-loop to pull water over the side of the tank, but I have found that to be very trouble prone. As long as the tank is empty, you will spend much less time drilling a hole to feed the close-loop system than you will playing with the plumbing later. I have a collection of bizarre PVC assemblies that I call my "sculpture garden", which is a testimony to how much time and money can be spent trying to avoid drilling a hole.


The plumbing plan sounds great. You have really done your homework. The overflow design sounds very sexy. I don't have those skills. I just bought 2 pieces of glass. I went full length not only for efficiency, but because it was easier to build.

You are correct about running the Mag24 inline. I have friends that have run a Mag 18 external for years with no problem, but I think is is best to avoid it. A practical solution I have seen is to put the closed-loop Mag pump in the sump. You still plumb it as a closed-loop but you stick in in the sump so it can leak and rattle without worries.

The other pumps you are looking at are all very nice. Lots of people are using the Dart and I have never heard anything but praise. You are going to have spectacular flow. I have seen a Dart really stir up a 180.

Anthony or one of his friends will have to weigh in on the manifold design. I just threw money at my last tank and went with Tunzes.

With all that excellent flow in a 90 gal, you may have to worry about the substrate. I have gone to Starboard with epoxy sand myself.

I admire your diligence. You are either very disciplined or scared of what your sister will do to you if your screw up the tank!

Good luck Paul.

[captbunzo]

Thanks again for the excellent response - and yes, I am probably both disciplined and scared. Obsessed is another word for it. Perfectionist? And with resources such as Reef Central, WetWebMedia, Reefkeeping.com, and Advanced Aquarist, there is so much good information available online.

Ok - so I will go for two 1.5 inch holes for the overflow. And one 2 inch hole for the closed loop (sorry - I may have forgot to mention that part in my last pump).

It is pretty important to keep this as error-proof as possible.

And I think the dart was a great find - excellent price for what looks like a really impressive pump.

[las]

bump

[captbunzo]

Ok. Here is my next question...

Closed Loop Intake Questions

Intake Count & Size

Our Sequence Reeflo Dart pump is going to suck a heck of a lot of water out of the tank. Of course, I have the normal concern of hurting fish and other critters that may swim to close.

To help with this, there are a couple if intake strainers that I am considering: big little.

However, with either of them, I still have to decide how many intake holes to use. The dart has a 2" intake and will suck about 3000 GPH (or so). The two main options I am considering are:

    1. One 2" hole
    2. Two 1.5" holes

Of course, I could also go with 3 or 4 intake holes or so, if that is recommended. If I got up to 4 holes, I can probably use smaller holes. The area of 4 - 1 inch circles is the same as 1 - 2 inch circle. Of course, I am sure the smaller holes would incur more static pressure loss, but probably not a big deal since the 1" holes would IMMEDIATELY Tee into a 2 inch line. So that leaves us with another option
    3. Four 1" holes

Now, the downside of more holes is that I have more chances to break the tank, etc. The upside would be, of course, lower flow per intake hole, and distributing that flow across the tank more.

One benefit of the smaller holes is that I can then get a glass drill bit that will cut those holes, instead of having to dremel them all.

What do I REALLY need to consider as far as the number of these holes. Will I be JUST FINE with fewer larger holes, and maybe that big strainer?

Vertical Placement

The other question is exactly where I want to place them, vertically. I would assume that about 4 inches above the sandbed would be great. Is that a reasonable option?

Anyhow, let me know what you think?

[captbunzo]

Anyone, please?

[captbunzo]

Ok. Let me sum up a couple of things here.

First, I REALLY need some help coming to a decision about the intake(s) for the closed loop.

Now, I have had recommended (in another thread) by Anthony that the closed loop intake NOT include any elbows between the tank and the pump. Unfortunately, do to space requirements in the room, That is not going to be possible.

So, Question 1 is: What can I do to help overcome the static pressure loss introduced by this elbow. The basic concept, I believe, is to provide interior pipe volume. That can be either a BIGGER pipe, or MORE pipes.

Unfortunately, I am limited at going any bigger then the 2" intake on the pump do to the various types of intake strainers that I have been able to find. So, that leaves the option of using MORE pipes.

So, assuming this is the option of choice, the idea is to provide either (a) two 2 inch holes, (b) two 1.5 inch holes, or (c) three 1.5 inch holes. The 1.5 inch option is explained next.



Question 2 is concerning the best way to avoid damage to livestock do to the intake strainers. If you look at the two strainers linked above, I really like the idea of the big beefy ones. I think they could be sufficiently hidden behind the rock and would do the best to diffuse the suction of the intake.

Unfortunately, the big strainer max size available is for a 1.5 inch hole. So I would have to go with the 2/3 hole option in that size.

So, am I being silly? Will the normal looking strainers really be just fine? Or is there a better way to provide "protection" around them then using the big strainers?

So, that's it, I think. Any clarifications of anything else from the above thread would be good, too.

I think I really just need to get figured out what is the best plan for the number & size of intakes, and the type of strainers to use.

Thank you all for your time and energy!

[mwood]

Look for a farm and home store in your area. Specifically look for a sprayer parts store. A farm and home store near my house has the big strainers for 2" holes.

[Reefvet]

Originally posted by captbunzo
Now, I have had recommended (in another thread) by Anthony that the closed loop intake NOT include any elbows between the tank and the pump. Unfortunately, do to space requirements in the room, That is not going to be possible.

Is there enough room to use soft tubing? A gentle bend or arc of the soft stuff can minimize the loss of intake volume, particularly in comparison to a hard right angle.

You don't mention if this is a glass or plexi tank. You could cover your intakes with gutter guard. Depending on what type of tank there are a couple of different adhesives that would do the trick. Gutter guard isn't pretty, but making it flush, and with coraline on it in time, it can be a lot less noticeable than the typical strainers.

[captbunzo]

It is glass. There may be enough room to use flexible tubing. Spa Flex may be an interesting choice...

[Reefvet]

You could cover the intakes with gutter guard and simply silicone it in place.

Spaflex or just large vinyl tubing could solve your problem.

Also, one of the reasons to avoid the hard angles with an intake is the cavitation that can take place. Any air that's taken can accumulate at the elbow and make for a noisy CL.

[bvoss]

I'm not an expert on closed-loops but I have made plenty of mistakes on them. I can confirm Anthony's point about elbows on the intakes. I gave me plenty of trouble with cavitation and microbulbles. Spaflex is the logical fix for this I think.

Two 1.5" holes leading to a 2" drain pipe. may be a good solution for the intake. I have a friend with that exact plumbing setup with a Dart and it works very well for him. He takes takes 1.5" spaflex into a 2" "Y-type" drain fitting. Then he takes 2" spaflex to the Dart intake.

Gutter guard is a good choice for intakes if you are going to hide them behind rocks. If not, those big strainers would probably work. Your suction will not be too extreme with two intakes.

Just a word of caution, you are putting a massive amount of flow into that 90 gal. I have seen Darts really stir up 180s.

I hope that helps. But as I have said before, this is why I went to Tunzes. By the time I went through all the effort for engineering a closed loop, they started looking pretty attractive.