Hi all,
I just got my new Waterbox 130.4 a couple of weeks ago and this is my first tank with a sump. Waterbox claims that there overflows are dead silent and others seem to agree but I can't get it to silence no matter what I do.
Here is the equipment
Aquarium WaterBox 130.4 with Herbie Overflow and 40 gallon sump
Overflow box with Herbie design, 1 inch pipes (but metric equivalent)
Vectra S2 Return Pump
MP40 Pumps x 2
I know the basic theory. So, basically, open the drain all the way then make small adjustments until a trickle is going in the emergency/secondary pipe. If too much water is going in the overflow then open the gate valve a little and if no water is going in the emergency/secondary and the water level drops towards the main drains then close the gate valve a little and give it some time between adjustments to balance out. That all sounds good in theory but it is not working for me.
I have calibrated my Vectra S2 DC pump, the drain pipes are an inch or so below the water level in the sump, the emergency/secondary drain pipe in overflow is 1/2 to 1 inch below the weir teeth. The main drain is another 4-5 inches below the emergency drain. The pipes were all cut and sized and shipped by @Waterbox Aquariums so I trust they know what they are doing.
Here is the main problem. No matter how precisely I try to match the flow using the gate valve the water level in the overflow box doesn't stay constant. If I had my gate valve open too little then water will constantly be flowing in the emergency drain. If I had it open too much then water will be dropping to the main drain pipe and I will get gurgling sounds. However, what I observe is that the water level drops about 1/2 inch below the secondary drain then it slowly rises over the next 2-3 minutes and then begins to flow in the emergency drain and then I get a flushing sound then it drops back 1/2 inch below the emergency drain and then rises again. This pattern keeps on repeating and no amount of gate valve adjustments seems to fix it. (See the video below which shows this fluctuation)
What I think is happening is that air gets in the main drain and reduces the water passing through it. This makes the water level rise and eventually when it reaches high enough, it is able to flush that air out due to extra height above the drain. Once the air is flushed then the water level drops and then the process starts all over again. Now, the question is how is the air getting in the main drain? The main drain is completely submerged and running for a long time so it has had time to purge all the air from pipe (theoretically). I don't see any vortex forming in the overflow that could suck the air, yet you will see in the video that tiny bubbles are constantly coming out of the main drain in the sump. The only possible cause I can think of is that the waterfall in the overflow box is creating some bubbles and those bubbles are getting sucked down in the main drain where they get trapped and reduce the flow of water until the water level rises enough to flush them out which causes the water level to drop causing bigger waterfall which creates bubbles in overflow and that process repeats.
One other observation I had was that when I turn off my MP40s, I am able to balance the flow much better and I can get it to almost silence and I don't get the fluctuating levels in the overflow. Now, I am not really generating a lot of waves on the surface of the water but maybe it is occasionally pushing too much water in the overflow? I even tried to move the MP40's lower but that doesn't have any effect. Now, I cannot turn off the pumps. What could be the solution? See at the end of the video where I got the overflow to be silent with the pumps off. This also means that the Vectra return pump is fine and the fluctuating water level is not because of the variance in return flow.
a) I was thinking to place something in the overflow box to break the waterfall so it doesn't generate the bubbles which could be sucked down in the drain
b) Raise the emergency drain a little bit so the water level is always higher and has enough volume of water above the main drain to flush any air that gets in. I was thinking to add 2 90 degree couplers but there is very little room on top as you can see in the video due to the return pipe above and because Waterbox uses metric pipes so it will be hard to find
c) I could cut the main drain and move it lower to achieve the same effect (volume of water above it will increase to flush the air but there is a strainer on top and I am not sure if it is glued or slip-on)
d) figure out some other way
I am open to your ideas on what is causing this fluctuating water level and how to fix it. Many thanks in advance.
Here is the video
Video showing what's happening ....
Here are a couple of pictures. Don't mind the scape, I just threw some rocks in there for now since I am going on vacation for 3 weeks and didn't have time to build a proper scape. I will do it when I come back.
I just got my new Waterbox 130.4 a couple of weeks ago and this is my first tank with a sump. Waterbox claims that there overflows are dead silent and others seem to agree but I can't get it to silence no matter what I do.
Here is the equipment
Aquarium WaterBox 130.4 with Herbie Overflow and 40 gallon sump
Overflow box with Herbie design, 1 inch pipes (but metric equivalent)
Vectra S2 Return Pump
MP40 Pumps x 2
I know the basic theory. So, basically, open the drain all the way then make small adjustments until a trickle is going in the emergency/secondary pipe. If too much water is going in the overflow then open the gate valve a little and if no water is going in the emergency/secondary and the water level drops towards the main drains then close the gate valve a little and give it some time between adjustments to balance out. That all sounds good in theory but it is not working for me.
I have calibrated my Vectra S2 DC pump, the drain pipes are an inch or so below the water level in the sump, the emergency/secondary drain pipe in overflow is 1/2 to 1 inch below the weir teeth. The main drain is another 4-5 inches below the emergency drain. The pipes were all cut and sized and shipped by @Waterbox Aquariums so I trust they know what they are doing.
Here is the main problem. No matter how precisely I try to match the flow using the gate valve the water level in the overflow box doesn't stay constant. If I had my gate valve open too little then water will constantly be flowing in the emergency drain. If I had it open too much then water will be dropping to the main drain pipe and I will get gurgling sounds. However, what I observe is that the water level drops about 1/2 inch below the secondary drain then it slowly rises over the next 2-3 minutes and then begins to flow in the emergency drain and then I get a flushing sound then it drops back 1/2 inch below the emergency drain and then rises again. This pattern keeps on repeating and no amount of gate valve adjustments seems to fix it. (See the video below which shows this fluctuation)
What I think is happening is that air gets in the main drain and reduces the water passing through it. This makes the water level rise and eventually when it reaches high enough, it is able to flush that air out due to extra height above the drain. Once the air is flushed then the water level drops and then the process starts all over again. Now, the question is how is the air getting in the main drain? The main drain is completely submerged and running for a long time so it has had time to purge all the air from pipe (theoretically). I don't see any vortex forming in the overflow that could suck the air, yet you will see in the video that tiny bubbles are constantly coming out of the main drain in the sump. The only possible cause I can think of is that the waterfall in the overflow box is creating some bubbles and those bubbles are getting sucked down in the main drain where they get trapped and reduce the flow of water until the water level rises enough to flush them out which causes the water level to drop causing bigger waterfall which creates bubbles in overflow and that process repeats.
One other observation I had was that when I turn off my MP40s, I am able to balance the flow much better and I can get it to almost silence and I don't get the fluctuating levels in the overflow. Now, I am not really generating a lot of waves on the surface of the water but maybe it is occasionally pushing too much water in the overflow? I even tried to move the MP40's lower but that doesn't have any effect. Now, I cannot turn off the pumps. What could be the solution? See at the end of the video where I got the overflow to be silent with the pumps off. This also means that the Vectra return pump is fine and the fluctuating water level is not because of the variance in return flow.
a) I was thinking to place something in the overflow box to break the waterfall so it doesn't generate the bubbles which could be sucked down in the drain
b) Raise the emergency drain a little bit so the water level is always higher and has enough volume of water above the main drain to flush any air that gets in. I was thinking to add 2 90 degree couplers but there is very little room on top as you can see in the video due to the return pipe above and because Waterbox uses metric pipes so it will be hard to find
c) I could cut the main drain and move it lower to achieve the same effect (volume of water above it will increase to flush the air but there is a strainer on top and I am not sure if it is glued or slip-on)
d) figure out some other way
I am open to your ideas on what is causing this fluctuating water level and how to fix it. Many thanks in advance.
Here is the video
Video showing what's happening ....
Here are a couple of pictures. Don't mind the scape, I just threw some rocks in there for now since I am going on vacation for 3 weeks and didn't have time to build a proper scape. I will do it when I come back.