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I've done something very wrong with my closed loop it seems.


CHUBAKAH

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Yes, and the flow is dramatically increased, but you already knew that.

 

I was considering This device to cure the problem, but it looks as though thats going to give me the option to have two lines of two heads each.

 

I'm sure it will be better than what I have now, but my question remains how much flow do I really need to be successful?

 

Is there some kind of rate I am looking to accomplish?

I am going to try one of those in a current project....IMHO, they are a new design...might want to wait a bit.

 

Do you have a 400-600gph power head to compare the single output flow too? If they are similar, it could give us a baseline to tweak from. If greater, a solution allow 2 to run at a time, if less, a single output at a time :)

 

Flow demands will depend on your target species, I am not an SPS guy, but I know my anemones are upset with me if my alternating flow is below the "400-600gph" ranges. I am under the impression sps would like much greater, but best to hear from more experienced folks.

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Again, I think that the SCWD on the output side won't make a large difference unless you improve the ability of the pump to take water in. For example, I have 2 closed loops on my tank that go through 10 returns. The feed for each of these pumps is 1.5" and they both run through Sequence Barracudas. One of the loops returns through 8 different returns, each of which is 1", but approximately 3.5 of them are running at one time (I say 3.5 because I use an Oceans Motions 8 way return, so essentially, 2 are always full force and 2 others are probably about 3/4 open). I also run another closed loop off of the same feed, 1.5", which returns through two 1" returns. The feeds themselves are each divided into two 1.5" strainers, this allows the flow to be good, but also reduces the velocity on the feed so that fish don't get sucked into them (which has still happened).

 

In your case, by adding the SCWD (I would wait to see how well it works from a longevity standpoint, first, as the 1" are fairly new to the market from what I understand and the knock on SCWDs before was that they were prone to failure and SIGNIFICANTLY reduced flow, despite the claims to the contrary), you will hopefully even out how your feed works. I would still, however, increase the pipe diameter.

 

Think of it like the internet. Have you seen where they compare phone lines to cable to T1 or whatever lines? They liken it to pouring water through a straw (not much flow) versus pouring it through 6" pipe. The ability of the water to actually get to the pump itself is what is restricting a lot of your flow and it is being compounded by the fact that it's being split up too much for a smaller size pump. Heck, for my system I got a lot of recommendations to increase the size of the pipe diameter throughout, regardless of the size of the eventual bulkhead that connected it back to the tank. One other thing that will help to alleviate some of the friction is to use flexible PVC/spaflex. This eliminates some of the friction caused by right angles and joints.

 

As far as flow is concerned, my advice is to start with more flow which can be reduced. Most pumps will use less energy if you reduce the flow on the return side and will be damaged if you restrict the intake or feed side. You can either add a ball valve somewhere to restrict flow or, better yet, simply play around with how your return is. The smaller the return itself, the more velocity and hence, more turbulent flow. The larger it is, the gentler the flow.

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davelin315,

So if I understand you correctly, I can leave the same bulkheads, and just increase the pipe diameter on the return back to the pump, and your thinking this is going to make a significant change?

 

I'm sure I could go up to a 2" pipe if it will make a change, I just have no experience to know for sure.

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One 2X4 on end, 24 inches long, will support 19,000+ pounds before it deflects sideways enough to fail. Given what appears to be 30(ish)" it's likely closer to 15,000 pounds - I'd say safe.

 

As long as you don't bump it next time you're underneath the tank working on that plumbing. I'm with flowerseller on this one. Not enough lateral support for my comfort level. But then, you're (Chubakkah) a GC and the only thing I knew about construction before building my stand was how to build bunkers strong enough to withstand a SCUD missile impact -- so I wouldn't be surprised if my designs tended to be on the "overbuilt" side. :)

 

As far as the CL:

 

IMO the problem is probably not too little flow but not enough velocity and therefore currents. I don't think it is so much that you are experiencing significant head loss due to friction, it is more the fact that you are dividing it by 4 and especially the fact that your outlets are 1" wide. Even with 0 head loss, 300 gph through a 1" outlet isn't going to feel like much, and it isn't going to move much water very far from the outlet (so it isn't going to create lots of currents that bounce off of things and each other and give nice turbulent flow). My advice would be to reduce the size of those outlets and see what effect that has. Simple way to do this would to stick a 1" - 1/2" reducer bushing in the end of them. This will increase the pressure the pump has to push against and therefore reduce the flow, but the increase in velocity might give you more of the effect you are looking for.

 

The best way to determine if your flow is adequate for your needs (whatever those may be) is to put something in your tank that will react to the flow like a piece of food or something.

 

Also, do you have ball valves b/n those true unions and the bulkheads underneath the tank?

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As long as you don't bump it next time you're underneath the tank working on that plumbing. I'm with flowerseller on this one. Not enough lateral support for my comfort level. But then, you're (Chubakkah) a GC and the only thing I knew about construction before building my stand was how to build bunkers strong enough to withstand a SCUD missile impact -- so I wouldn't be surprised if my designs tended to be on the "overbuilt" side. :)

I can't tell you how many times I have LMAO in the last year reading and watching people over build the H-E-double hocky sticks out of stands, and only a few times have I ever seen anyone say a thing about the house structure.

 

Also, do you have ball valves b/n those true unions and the bulkheads underneath the tank?

Actually the four return lines are in the floor of the tank approx 3" from the front of the tank.

 

The other answer is NO, I did not put ball valves in, as I wasn't even thinking I would have to adjust flow having all of the turns, and sizing the same. Of course I realize now I screwed up. I still think I can do that, as I did leave myself some room.

 

Thanks a lot for your advice as well. At about two dollars to check this theory, I like it the best.

:biggrin:

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Just some thoughts. I'm no expert on these matters but maybe something here will prove useful. Rough calculation using Reef Central's head loss calculator on the plumbing both in front of and behind your pump say you're losing on the order of 12.7 (3.9 meters) of head from the plumbing. Now, looking at the pump's performance graph, you see that the manufacturer says you should see about 5 liters/minute of discharge (1.3 gallons per minute). At 231 cubic inches per gallon, that's about 300 cubic inches per minute, or 5 cubic inches per second. Divide that by the total square inches of outflow (4 x 1-inch pipe = 3.14 square inches) and you get a linear flow of 1.6 inches per second out of your outlets (theoretically).

 

Compare that to a Maxijet 1200 (295 gph out of a 1/2" exit at 0' head loss) that moves water linearly at about 96 in/sec and now you have a comparative reference with your 1270 gph pump. Of course, you probably don't want maxijet velocities out of your returns but it's just a convenient reference.

 

Upsizing your plumbing to 1.5 inches, according to RC's head loss calculator drops your head loss to about 2.7 feet (a 10-foot improvement!); with 2 inch plumbing, the drop is less than 1-foot of head pressure. I think Dave's right on the mark with the suggestion to upsize your plumbing. Hope this helps.

Edited by Origami2547
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Just some thoughts. I'm no expert on these matters but maybe something here will prove useful. Rough calculation using Reef Central's head loss calculator on the plumbing both in front of and behind your pump say you're losing on the order of 12.7 (3.9 meters) of head from the plumbing. Now, looking at the pump's performance graph, you see that the manufacturer says you should see about 5 liters/minute of discharge (1.3 gallons per minute). At 231 cubic inches per gallon, that's about 300 cubic inches per minute, or 5 cubic inches per second. Divide that by the total square inches of outflow (4 x 1-inch pipe = 3.14 square inches) and you get a linear flow of 1.6 inches per second out of your outlets (theoretically).

 

Compare that to a Maxijet 1200 (295 gph out of a 1/2" exit at 0' head loss) that moves water linearly at about 96 in/sec and now you have a comparative reference with your 1270 gph pump. Of course, you probably don't want maxijet velocities out of your returns but it's just a convenient reference.

 

Upsizing your plumbing to 1.5 inches, according to RC's head loss calculator drops your head loss to about 2.7 feet (a 10-foot improvement!); with 2 inch plumbing, the drop is less than 1-foot of head pressure. I think Dave's right on the mark with the suggestion to upsize your plumbing. Hope this helps.

I used the calculator myself, and I know the exact lengths and came up with 12.8 myself, so I think that is not far of if at all.

 

I'm going to head off to the store now and try both up sizing my return to the pump, and downsize the jets at the tank, and I'll report back later this evening with my results.

 

I really do appreciate all of the feedback from everyone!

You guys and gals rock!

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IMO the problem is probably not too little flow but not enough velocity and therefore currents. I don't think it is so much that you are experiencing significant head loss due to friction, it is more the fact that you are dividing it by 4 and especially the fact that your outlets are 1" wide. Even with 0 head loss, 300 gph through a 1" outlet isn't going to feel like much, and it isn't going to move much water very far from the outlet (so it isn't going to create lots of currents that bounce off of things and each other and give nice turbulent flow). My advice would be to reduce the size of those outlets and see what effect that has. Simple way to do this would to stick a 1" - 1/2" reducer bushing in the end of them. This will increase the pressure the pump has to push against and therefore reduce the flow, but the increase in velocity might give you more of the effect you are looking for.

At $2.40, I made this change and BAM!

 

The velocity is hitting the back of the tank. :rollface:

 

I'm still going to change the return from the tank to the pump to 1 1/2" PVC, and I would have done that tonight, but realized a few minutes ago I forgot three couplings. :eek:

 

I'll head out to Home Depot tomorrow AM and make the rest of the changes.

0095.gif

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At $2.40, I made this change and BAM!

 

The velocity is hitting the back of the tank. :rollface:

 

I'm still going to change the return from the tank to the pump to 1 1/2" PVC, and I would have done that tonight, but realized a few minutes ago I forgot three couplings. :eek:

 

I'll head out to Home Depot tomorrow AM and make the rest of the changes.

0095.gif

Great news. Photos....we want photos!!!

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If you are feeling very little flow, I've got to think either we differ on what "little flow" is, or there is something wrong with the pump or plumbing... check valve is facing the wrong way, or the impeller isn't spinning or somehting is clogging the line... I don't see enough head loss to justify it.

 

I agree with Chip. I wouldn't get under that stand. It isn't the load bearing weight of the pine. (I thought it was 1,200 #s / sq inch, so a finished 2*4 would be 1.5x3.5 about 2.5 tons) but the strength of the joints. It looks like all you have holding that thing in place is 2 end screwed but joints... not very strong.

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Glad that worked.

 

My thought about the ball valves was not actually that you would use them to control the flow, but that it would give you a way to change your plumbing later on if you ever decided you wanted to modify something for whatever reason. Without them, I don't think you'd want to go unscrewing those true unions with a full tank of water in there. :)

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I'm no expert on building anything, but I think the diagonal supports on the side combined with the pieces close to the floor will stabilize it enough. It is appears to be attached to the wall so I ASSume that adds something. It would take quite a bump to get that thing to sway.

 

Just my $.02. I have an AGA stand :).

 

 

As long as you don't bump it next time you're underneath the tank working on that plumbing. I'm with flowerseller on this one. Not enough lateral support for my comfort level. But then, you're (Chubakkah) a GC and the only thing I knew about construction before building my stand was how to build bunkers strong enough to withstand a SCUD missile impact -- so I wouldn't be surprised if my designs tended to be on the "overbuilt" side. :)

 

As far as the CL:

 

IMO the problem is probably not too little flow but not enough velocity and therefore currents. I don't think it is so much that you are experiencing significant head loss due to friction, it is more the fact that you are dividing it by 4 and especially the fact that your outlets are 1" wide. Even with 0 head loss, 300 gph through a 1" outlet isn't going to feel like much, and it isn't going to move much water very far from the outlet (so it isn't going to create lots of currents that bounce off of things and each other and give nice turbulent flow). My advice would be to reduce the size of those outlets and see what effect that has. Simple way to do this would to stick a 1" - 1/2" reducer bushing in the end of them. This will increase the pressure the pump has to push against and therefore reduce the flow, but the increase in velocity might give you more of the effect you are looking for.

 

The best way to determine if your flow is adequate for your needs (whatever those may be) is to put something in your tank that will react to the flow like a piece of food or something.

 

Also, do you have ball valves b/n those true unions and the bulkheads underneath the tank?

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Are you guys still scurd about the stand?

 

You should be more scurd about the house your in then. I've been building houses for 28 years, and I haven't had one fall yet!

 

:wink:

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Are you guys still scurd about the stand?

 

You should be more scurd about the house your in then. I've been building houses for 28 years, and I haven't had one fall yet!

 

:wink:

 

They haven't been filled with water either. :biggrin:

j/k

We're ALL only trying to help and look out for our fellow reefers.

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I guess I should start going in to threads where people are over building their stands, and watch out for fellow carpenters.

LMAO

 

Just kidding guys!

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I guess I should start going in to threads where people are over building their stands, and watch out for fellow carpenters.

:clap: Might be a good idea, save a tree or two :biggrin:

 

At $2.40, I made this change and BAM!

 

The velocity is hitting the back of the tank. :rollface:

 

I'm still going to change the return from the tank to the pump to 1 1/2" PVC, and I would have done that tonight, but realized a few minutes ago I forgot three couplings. :eek:

You have increased the perceived flow......the velocity, but using the 1/2" outputs you have actually decreased the actual flow (volume) - kinda funny how that works. The 1.5" will increase the actual flow amount considerably & and you can leave the 1" outlets & still get the velocity increase............if that's what you want. :biggrin:

 

As long as you don't bump it next time you're underneath the tank working on that plumbing. I'm with flowerseller on this one. Not enough lateral support for my comfort level.

Sir Issac Newton is your friend - bodies in motion & at rest....aka...interia. It would take quite a large bump to get such a heavy load moving, might even be greater than your cranium can bear (or generate). Also, remember another of Newton's discoveries - for every action there is an equal & opposite reaction. Okay, so in this case we get a couple, two, tree guys to push on the rear of the tank in an attempt to get it moving.............the front will (must) move in the opposite direction = it can't move so the rear???? (well, the front could but then there'd be slightly more trouble, as in the wall...........but I digress.

 

I'm no expert on building anything, but I think the diagonal supports on the side combined with the pieces close to the floor will stabilize it enough. It is appears to be attached to the wall so I ASSume that adds something. It would take quite a bump to get that thing to sway.

Brings up some good points, this stand actually demonstrates very well how to deal with loads & how loads can be transferred. You'll notice the front is a wall which is a) long b) drywalled c) connected to other "stuff" = it has a large amount of lateral (side to side in the #2 picture) stability (duh, it's a house). You'll notice the rear top is tied to the front via a frame & sheeting = the rear top has lateral stability. Now take note of the lower legs, see the cross piece? That transfers the load across the bottom = no point load AND it ties the two legs together (one can't fold on it's own). See the two short pieces that run from the cross member to the front wall? That ties the rear assembly to the front wall = the bottom has lateral stability. The final piece is the angled pieces = massive front to back lateral stability = if the wall don't move the tank ain't gonna (and is supports the cantilevered area.

 

It's a really nice example of how little lumber it takes to build a stand that holds the load. We always tend to think of a XXX gallon tank weighs YYYY pounds, sounds like a lot but it's a) spread out over a decent area b) the weight actually works for you to an extent c) lumber, when used properly has a great deal of strength (kinda why we build houses with it).

 

Upsizing your plumbing to 1.5 inches, according to RC's head loss calculator drops your head loss to about 2.7 feet (a 10-foot improvement!); with 2 inch plumbing, the drop is less than 1-foot of head pressure. I think Dave's right on the mark with the suggestion to upsize your plumbing. Hope this helps.

Yep, the larger the pipe the less surface area (friction) relative to the volume of water = less friction loss = more output for a given pump. Much the same as pumps have a "head loss curve", pipes are the same the friction loss is a curve. For simplicity RC calls it a head loss calculator, but for a closed loop it's entirely friction loss - bigger pipes = less friction = more flow.

 

Careful what you ask for - the actual flow is going to go up a LOT with 1.5" plumbing, toss in the velocity increase from the 1" outlets......................???

Edited by ErikS
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Careful what you ask for - the actual flow is going to go up a LOT with 1.5" plumbing, toss in the velocity increase from the 1" outlets......................???

I'll pull the reducers out before I turn the pump back on just in case it does go up a lot.

 

On tank stands, anything more than your standard framing 16" on center is over kill.

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I'll pull the reducers out before I turn the pump back on just in case it does go up a lot.

 

Aw, just leave 'em in and see how far they shoot :biggrin:

 

 

Careful what you ask for - the actual flow is going to go up a LOT with 1.5" plumbing, toss in the velocity increase from the 1" outlets......................???

 

Flow is what you want though. That's why you're installing a closed loop. It's good that you have that ball valve available though to throttle it back some if needed.... Heck, having the headroom at your disposal to increase the flow is probably something desirable on occasion so you can create "storms" when needed to shake things up some.

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heheh. I'm just trying to get some tank stand conversation going so I can LEARN something :).

 

Are you guys still scurd about the stand?

 

You should be more scurd about the house your in then. I've been building houses for 28 years, and I haven't had one fall yet!

 

:wink:

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Aw, just leave 'em in and see how far they shoot :biggrin:

Flow is what you want though. That's why you're installing a closed loop. It's good that you have that ball valve available though to throttle it back some if needed.... Heck, having the headroom at your disposal to increase the flow is probably something desirable on occasion so you can create "storms" when needed to shake things up some.

Yep - lol - given I'm in the "no such thing as too much flow" camp......................

 

Didn't mean to imply it would be too much, just to be aware it's going to be a lot more.

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Well I just finished making the two changes.

 

I added 1" to 1/2" reducers [last night] and that had made a pretty significant change.

 

Today I ripped out the 1" line back to the pump and changed it to 1 1/2". While it for sure made a difference, It's not near as substantial as I thought it would be.

 

Is the current flow going to be enough? I am hoping it will be, but since I haven't glued in the reducers I think I could even add in some of those whatchamcallits with the flex lines.

 

In any event, I think the problem is at the very least MUCH MUCH better.

 

Looks like I will be going to see the good Dr Mac this weekend after all.

 

I took the ending result picture from the side so what I have done so far is viewed, but I'll get a new thread up shortly with the project.

tank2004xb7.jpg

 

Thanks again team!

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Interesting. The calculations I'd used were for a total change out to 1-1/2 inch (on both sides) which could obviously get more complicated and expensive. Any idea what kind of flow you're getting now?

 

Nice shot, by the way, of your stand.

Edited by Origami2547
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Interesting. The calculations I'd used were for a total change out to 1-1/2 inch (on both sides) which could obviously get more complicated and expensive. Any idea what kind of flow you're getting now?

That's alright, my original estimate included all the fittings at the top which in this picture appear to be returns from the sump :blush:
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