Overflowing one tank into two tanks equally?

[Cecil]

I'm going to set up two RAS tanks this fall vs. just one, but MAY use the same RBC for both, which will be in a separate tank. If I do so, there will be two pumps pumping water from the each clarifer drum associated with each tank to the RBC, which in turn drops water back to the two tanks via gravity via two overflow pipes.

My question is, how difficult will it be to gravity flow an equal amount of water back to the two tanks? (50 percent to each tank) Should I add valves to adjust the flow if more water wants to go to one tank?

My guess is, if the RBC tank is level, and the outflows are the same diameter pipe at the same level, the flow should be equal going to each tank and any adjustment with a valve will not be needed.

What say you?

[Ravnis]

I've tried the same principle going from the fish tank to two grow beds by gravity. I should work, but I always had problems build up affecting the flow and one getting more than the other. I would install valves, if nothing else as a back up system. My 0.02.

Of course I was also trying to flood and drain with an auto siphon, so flow rate was critical.

[Privatteer]

If the RAS are same hieght you could tie the 2 together say 1/2 way up the wall. That way any differential in flow will equalise. If you had a valve on the tie, and on the 2 overflows you would still be able to isolate one RAS for cleaning.

[Cecil]

If the RAS are same hieght you could tie the 2 together say 1/2 way up the wall. That way any differential in flow will equalise. If you had a valve on the tie, and on the 2 overflows you would still be able to isolate one RAS for cleaning.

Thanks all for the responses. I especially like the pro of being able to isolate one RAS for cleaning as is highlighted.

[kellenw]

Cecil - You could use a couple of float valves.

[Cecil]

Cecil - You could use a couple of float valves.

How would that work? I'm not familar with float valves.

[kellenw]

Think of a contraption similar to the float bulb in your toilet. As the bulb floats higher, it restricts flow to that tank. As it floats lower, it allows increased flow.

Perhaps an even better way to accomplish this would be to use a float bulb and push rod design with an adjustable height weir. It's like a floating, self adjusting mini-dam that allows water out of the reservoir tank (in your case your RBC tank) based on the water level of the tank below it (in your case one of the fish tanks). In order for this to work in a practical way, the RBC container must be gravity fed into the fish tanks and be positioned directly above them. A weir is essentially just a dam that water flows over the top of (remember this). So, you would install two weirs with floats and push rods in your RBC container, and they would be positioned such that the float bulb and push rod would go right into the fish tanks. When the water level goes down in one of the tanks, the float bulb in that tank goes down with it. This then causes the attached push rod to lower, resulting in the weir lowering as well, allowing water to spill over the top of it. This results in an extremely consistent water level in multiple tanks (technically an infinite number of tanks are possible) with the use of only one pump. It is really the most reliable solution in my opinion.

[Cecil]

Thanks Kellen!

[qommunity]

Would this work (or am I missing something)?

If the two tanks have the same water level (and all things being equal), you can just use a simple tube siphon with ends (filtered, if needed) that are set at the level where you want the equalization to stop.

Water flow will always go from the higher level tank to the lower one (whichever tank it may be).

Then when you dont want equalization (or to isolate the tanks), just remove the tube.

In case the water level falls below any end point of the tube, the siphon will simply stop (but it is easy to re-start anyway).

In the event that the tanks are NOT of the same level, then just put a bucket (or some form of buffer) at the proper level (with respect to the higher tank), and make sure that the tube end (and the original feed to the lower tube) flows in it, and that water then overflows properly into the lower tank.

With this approach, you can still get equal inflow to both tanks (even if they are of different levels) by simply increasing the capacity of the buffer/bucket to that of the expected volume.

Just a suggestion.

[Cecil]

Would this work (or am I missing something)?

If the two tanks have the same water level (and all things being equal), you can just use a simple tube siphon with ends (filtered, if needed) that are set at the level where you want the equalization to stop.

Water flow will always go from the higher level tank to the lower one (whichever tank it may be).

Then when you dont want equalization (or to isolate the tanks), just remove the tube.

In case the water level falls below any end point of the tube, the siphon will simply stop (but it is easy to re-start anyway).

In the event that the tanks are NOT of the same level, then just put a bucket (or some form of buffer) at the proper level (with respect to the higher tank), and make sure that the tube end (and the original feed to the lower tube) flows in it, and that water then overflows properly into the lower tank.

With this approach, you can still get equal inflow to both tanks (even if they are of different levels) by simply increasing the capacity of the buffer/bucket to that of the expected volume.

Just a suggestion.

I like your thinking. I'm a big proponent of the KISS principal too!