Pvc water bridge with micro water turbine generator

[jt8791]

So off the wall random idea I just had. Not sure if there is any way to make it feasible. Was already planning two 1” pvc water bridges to connect two tanks side by side.

Was wondering, in theory, if these micro water turbine hydroelectric generators are safe to use in saltwater, would it be possible to put one on each pipe connected to a dc return pump, pushing/pulling water each direction. Running on a loop connected to a battery.

Might be more of an electricians department but let know if anyone has ever tried it or looked into trying it.

not sure if those hydro generators put out their true 10w or how to wire that. Assume there would need to be a voltage regulator somewhere but other than that I’m clueless.

If this is something reasonable to pull off, it sounds much simpler than a battery backup. In reality if I was to go this route I should add overflow boxes with surface skimmer to hide the return pumps.

Figure it’s a shot in the dark but worth researching on. If it isn’t possible with what’s on the market now might be a future product idea. Does sound awesome, self powered tank, although I know it would be very complex to pull off

 

[Brett S]

I’m not quite sure what you’re going for, but there is no such thing as a self powered tank. The turbines work to generate power because they can be put in places where water flows naturally, but if you are using a pump to move water to spin the turbine too much energy will be lost to friction and heat. You will use more energy to power the pump than you would get back from the turbine.

Even putting the turbine in the feed from the pump will cause back pressure and you will need a bigger pump to get the same amount of flow, again, costing more power than you would get back from the turbine.

The only place you could potentially put a turbine and use ‘free’ water pressure would be in the drains for the water returning from the tank to the sump, but I suspect that there really wouldn’t be enough flow and pressure to make it worthwhile.

 

[Soren]

So off the wall random idea I just had. Not sure if there is any way to make it feasible. Was already planning two 1” pvc water bridges to connect two tanks side by side.

Was wondering, in theory, if these micro water turbine hydroelectric generators are safe to use in saltwater, would it be possible to put one on each pipe connected to a dc return pump, pushing/pulling water each direction. Running on a loop connected to a battery.

Might be more of an electricians department but let know if anyone has ever tried it or looked into trying it.

not sure if those hydro generators put out their true 10w or how to wire that. Assume there would need to be a voltage regulator somewhere but other than that I’m clueless.

If this is something reasonable to pull off, it sounds much simpler than a battery backup. In reality if I was to go this route I should add overflow boxes with surface skimmer to hide the return pumps.

Figure it’s a shot in the dark but worth researching on. If it isn’t possible with what’s on the market now might be a future product idea. Does sound awesome, self powered tank, although I know it would be very complex to pull off

Well, I do know that there is no such thing as perpetual motion. The pump would have to provide the energy that would be harvested at a loss by the generators. No system is 100% efficient, so the energy harvested must be less than the energy consumed by the pump just for powering the generators, which would be less than total pump energy consumption to overcome gravity to begin with.

 

[Brett S]

So off the wall random idea I just had. Not sure if there is any way to make it feasible. Was already planning two 1” pvc water bridges to connect two tanks side by side.

I wanted to make this a different post to avoid things getting confused. But again, I’m not sure what you are aiming for here. About the only thing a water bridge can be used for is a path for fish to move from one tank to another, but 1” PVC is probably a bit small for that. Two 1” pipes will not work to circulate water between the two tanks because you would need to pump it in both directions, but it’s impossible to have two pumps flow rates matched exactly. The water level in one tank would slowly lower while the water level in the other tank slowly raised until it overflowed.

You can use an overflow with a gravity drain to return water to a sump because the sump is physically lower than the tank, but it would not work if the sump was next to the tank.

 

[jt8791]

Oh okay, yeah I figured it wasn’t possible. I’ll just go back to the battery backup route on the wave pumps .

Is a pvc water bridge not a good solution to connect two tanks next to each other? That might put this hole build back at the drawing board.

My landlord won’t let me do any major plumbing, he even got nervous about two sealed pvc pipes coming out of the tanks.

 

[Brett S]

Oh okay, yeah I figured it wasn’t possible. I’ll just go back to the battery backup route on the wave pumps .

Is a pvc water bridge not a good solution to connect two tanks next to each other? That might put this hole build back at the drawing board.

My landlord won’t let me do any major plumbing, he even got nervous about two sealed pvc pipes coming out of the tanks.

The traditional way to connect two tanks next to each other would be to have them share a common sump. You would either have one large return pump that splits off to feed both tanks, or one return pump for each tank in the sump and then each tank would have it’s own overflow that feeds back into the common sump.

Alternately, if you don’t want a sump, then you could just run each tank independently.

If you can put the tanks at different heights, ideally one on top of the other, but as long as there’s a least a foot or two of elevation difference then you can use pump to send water from the lower tank to the upper tank and then use a traditional gravity overflow to return the water from the upper tank to the lower tank.

 

[Soren]

I wanted to make this a different post to avoid things getting confused. But again, I’m not sure what you are aiming for here. About the only thing a water bridge can be used for is a path for fish to move from one tank to another, but 1” PVC is probably a bit small for that. Two 1” pipes will not work to circulate water between the two tanks because you would need to pump it in both directions, but it’s impossible to have two pumps flow rates matched exactly. The water level in one tank would slowly lower while the water level in the other tank slowly raised until it overflowed.

You can use an overflow with a gravity drain to return water to a sump because the sump is physically lower than the tank, but it would not work if the sump was next to the tank.

I agree with everything you mentioned here, and it got me wondering: Is there any way to take advantage of a slight siphon between tanks to make up for the pump differences? Theoretically, the pumps would keep the bridge tubes filled and would create siphons between tanks that may allow for a difference in tank levels to create pressure differences and cause the flow of the pumps to balance better. I think this would require an additional inlet to the bridge tube than just the one connected to the pump, almost like a venturi system used to pull air into a skimmer. I also assume that this venturi tube would have to have some sort of check valve that may be hard to balance with the pump flow to avoid the pump from just sending water backwards through the venturi. I am just thinking about this now and have not considered it much, but I am wondering if there have been attempts to balance the flow between two pumps that ever had merit to a working system. Essentially, I am wondering if a balance might be achievable between flow rates, though this is obviously much more difficult than the typical sump overflow and return system.

I suppose the simplest way to make this work would be to use the pump to lift water into a small reservoir above one tank with an overflow into the other. By using another pump of slightly lower flow (tune-able with a valve) in the other tank, an over-the-tank siphon overflow could be achieved and maintained that allows for a siphoning between tanks with smaller difference in height (which difference would be maintained with the previous pump and reservoir similar to a typical sump overflow and return system).

I might have to do some research and experimentation on these ideas, as linked tanks are of interest to me.

 

[Brett S]

I agree with everything you mentioned here, and it got me wondering: Is there any way to take advantage of a slight siphon between tanks to make up for the pump differences? Theoretically, the pumps would keep the bridge tubes filled and would create siphons between tanks that may allow for a difference in tank levels to create pressure differences and cause the flow of the pumps to balance better.

Unfortunately not. The reason that siphons and overflows work is because of the height difference between the tanks. With a traditional overflow going into a sump you have the pressure of water trying to fall four+ feet to get into the sump.

However, with two tanks right next to each other the water level is the same, so the water won’t move from one tank to another. And even when they get out of balance and one’s water level is half an inch above the other that half inch just doesn’t create enough pressure to move water quickly enough to overcome the pump difference. The tank will overflow before gravity moves enough water through the siphon.

 

[Brett S]

If the tanks were linked with a large (5 or 6 inch diameter) pipe, then you might be able to get it to work, but certainly not with one inch pipe.

 

[Soren]

Unfortunately not. The reason that siphons and overflows work is because of the height difference between the tanks. With a traditional overflow going into a sump you have the pressure of water trying to fall four+ feet to get into the sump.

However, with two tanks right next to each other the water level is the same, so the water won’t move from one tank to another. And even when they get out of balance and one’s water level is half an inch above the other that half inch just doesn’t create enough pressure to move water quickly enough to overcome the pump difference. The tank will overflow before gravity moves enough water through the siphon.

I understand that siphon would not work on its own with minimal height, but wondered if it might be possible to use the slight height difference in conjunction with fine-tuning pumps to end up with a nearly exactly equivalent flow rate. As I think about it more, I do think I see many complications in attempting this. Even if somehow the flow rates were nearly perfectly matched, would I trust a system that has reasonable potential to overflow if a slight additional restriction occurred on one of the tubes? Definitely not my preference.

If the tanks were linked with a large (5 or 6 inch diameter) pipe, then you might be able to get it to work, but certainly not with one inch pipe.

I see how up-sizing the pipe could both help or hurt the concept, but I still think the final conclusion that I have right now is that the best way to join 2 tanks at the same water level would be with bridge tubes running straight between the tanks through drilled bulkheads (for the exact same reasons I choose drilled overflows rather than over-the-top: eliminating unwanted overflow out of the system).

 

[Brett S]

I understand that siphon would not work on its own with minimal height, but wondered if it might be possible to use the slight height difference in conjunction with fine-tuning pumps to end up with a nearly exactly equivalent flow rate. As I think about it more, I do think I see many complications in attempting this. Even if somehow the flow rates were nearly perfectly matched, would I trust a system that has reasonable potential to overflow if a slight additional restriction occurred on one of the tubes? Definitely not my preference.

Yeah, I think there are a lot of issues here. A restriction or a pump failure could cause disaster.

I see how up-sizing the pipe could both help or hurt the concept, but I still think the final conclusion that I have right now is that the best way to join 2 tanks at the same water level would be with bridge tubes running straight between the tanks through drilled bulkheads (for the exact same reasons I choose drilled overflows rather than over-the-top: eliminating unwanted overflow out of the system).

Even tanks connected through bulkheads will face the same issues with small diameter pipes. If you are trying to actively circulate water from one tank to the other you’re just not going to get enough water flowing through the pipe without a pump to keep up with a pump moving water from one tank to another.

If you aren’t trying to actively circulate water between the two tanks, then small diameter pipe (through bulkheads or up and over as a water bridge is fine. That will keep the tanks at the same water level, and as I said earlier, could provide fish a path from one tank to another. But if you do it this way you’ll need to make sure that each tank has it’s own filtration system or access to common filtration in a sump because the connections won’t be used to circulate water between the tanks.

 

[Soren]

Yeah, I think there are a lot of issues here. A restriction or a pump failure could cause disaster.



Even tanks connected through bulkheads will face the same issues with small diameter pipes. If you are trying to actively circulate water from one tank to the other you’re just not going to get enough water flowing through the pipe without a pump to keep up with a pump moving water from one tank to another.

If you aren’t trying to actively circulate water between the two tanks, then small diameter pipe (through bulkheads or up and over as a water bridge is fine. That will keep the tanks at the same water level, and as I said earlier, could provide fish a path from one tank to another. But if you do it this way you’ll need to make sure that each tank has it’s own filtration system or access to common filtration in a sump because the connections won’t be used to circulate water between the tanks.

Thanks for advising, Brett S.
I do not plan to link my tanks at the same water levels, so typical overflows should be enough, but I appreciate the recommendation on separate filtration if linked at the same water level through even drilled bulkheads. I see why there would be negligible natural flow between the tanks.

 

[jt8791]

Yeah the tanks would be the same height. I should have researched that more. Was only trying to connect the two tanks together as simply as possible without drilling but must have misunderstood the information I found on water bridges.

Wasn’t concerned with fish being able to pass through. Just a simple way to connect a 30 and 20 being same height, display and refugium. I should have known simple and saltwater don’t typically go together.

Wouldn’t be in this boat if it wasn’t for my landlord. Argued with him for 2 months on tank size. 55, 50 and 40 were way too big for a second floor according to him. Really don’t want to do a 30 gallon by itself, doesn’t even seem worth the money or work.

 

[Brett S]

Yeah the tanks would be the same height. I should have researched that more. Was only trying to connect the two tanks together as simply as possible without drilling but must have misunderstood the information I found on water bridges.

Wasn’t concerned with fish being able to pass through. Just a simple way to connect a 30 and 20 being same height, display and refugium. I should have known simple and saltwater don’t typically go together.

Can you put the refugium under the display tank rather than next to it?

Wouldn’t be in this boat if it wasn’t for my landlord. Argued with him for 2 months on tank size. 55, 50 and 40 were way too big for a second floor according to him. Really don’t want to do a 30 gallon by itself, doesn’t even seem worth the money or work.

Wait, so he doesn’t want you to have a 50G tank, but he has no problem with a 30 and a 20? I’m not sure I see the logic behind that... they will be the same weight and can cause the same amount of water to wind up on the floor in the event of a disaster.

 

[jt8791]

Yeah I don’t get it either, I’ll have to measure underneath the stand. Not sure it’s deep enough to fit a 20 under it, maybe a 10 but that wouldn’t be worth the effort.

Doing a 30 and 20 vs one 50 was my suggestion but should’ve known if it looks simple in a YouTube video it’s not gonna work. Having corals in the display and a tank next to it for macros was what had me interested the most.

Back to the drawing board I guess, half tempted to cancel the whole build.

 

[jt8791]

Hard to say having no experience in the plumbing area of reef tanks, every way I look up how to plumb a fuge all I can see happening is a flood.

Maybe I’ll have to give up on a 20 gallon refugium, I don’t know what I’m doing to plumb it properly. Suppose I could settle on a hob fuge but they hardly seem worth the money.

 

[jt8791]

Actually hold up, what if I put the 20 on a lower stand next to the 30? Could use the nightstand I had the last 20 on, held my first sw tank no problem.

Not sure if I should drill the tank or just use an hob overflow box on that side.

 

[jt8791]

So being a beginner I'm just gonna keep it simple, will drain and move the tank so I can add a hob refugium and skimmer later, thinking aquamaxx hob-r and hf-m.