Sump Help

[dR3ws3r]

Hi,

I have an Aquaforest 790 with an Aquaforest sump. Basically a 155 gallon display with internal overflow herbie drain. I'm running a Tunze osmolator ATO. I'm using a Sicce SDC 6 return pump.

My basic problem is with level stability in the return chamber. I live in Virginia, and we frequently have thunderstorms and power blips. Whenever that happens and the return pump stops for even a few seconds, the stability of the sump level goes to crap. It is like there are 100 possible levels that the sump will be happy at. Today we had a brief power loss, and my sump reset at a low level, and the ATO kept on filling the return chamber. This filled the display too high, and now I can hear the flow going down the emergency overflow. I had to basically mess around with the return valve until I got the level in the return chamber to where I wanted it again, and then find the valve position that matches the return pump flow.

Sometimes the opposite happens, and the sump level goes high when the pump stops for a few seconds, and continues to run in a high level state with the annoying alarm on the osmolator going off. It never seems to correct itself and even worse when it settles on a low level, I'm getting dilution from my ATO. There has got to be a better way to tune this thing. I'm fairly new to the hobby so all recommendation are welcome.

I've even considered getting a UPS just for the return pump, so that it never shuts off ... but I will still have this problem after every weekly water change.

What am I doing wrong? Certainly there has to be a way to balance the pump, tank level and return valve so that I don't have to adjust everything when the pump shuts off for just a few seconds.

 

[Dom]

Hi,

I have an Aquaforest 790 with an Aquaforest sump. Basically a 155 gallon display with internal overflow herbie drain. I'm running a Tunze osmolator ATO. I'm using a Sicce SDC 6 return pump.

My basic problem is with level stability in the return chamber. I live in Virginia, and we frequently have thunderstorms and power blips. Whenever that happens and the return pump stops for even a few seconds, the stability of the sump level goes to crap. It is like there are 100 possible levels that the sump will be happy at. Today we had a brief power loss, and my sump reset at a low level, and the ATO kept on filling the return chamber. This filled the display too high, and now I can hear the flow going down the emergency overflow. I had to basically mess around with the return valve until I got the level in the return chamber to where I wanted it again, and then find the valve position that matches the return pump flow.

Sometimes the opposite happens, and the sump level goes high when the pump stops for a few seconds, and continues to run in a high level state with the annoying alarm on the osmolator going off. It never seems to correct itself and even worse when it settles on a low level, I'm getting dilution from my ATO. There has got to be a better way to tune this thing. I'm fairly new to the hobby so all recommendation are welcome.

I've even considered getting a UPS just for the return pump, so that it never shuts off ... but I will still have this problem after every weekly water change.

What am I doing wrong? Certainly there has to be a way to balance the pump, tank level and return valve so that I don't have to adjust everything when the pump shuts off for just a few seconds.

If I understand your post, you're saying that every time there is a power outage the sump level changes when the power comes back on. Also, I understand that you are saying the level of water in the sump is random and varies from outage to outage.

This may be something specific to the Herbie.

Maybe re-post with the title "problem with Herbie overflow" and see what feedback you get from others that installed a Herbie.

 

[dR3ws3r]

If I understand your post, you're saying that every time there is a power outage the sump level changes when the power comes back on. Also, I understand that you are saying the level of water in the sump is random and varies from outage to outage.

This may be something specific to the Herbie.

Maybe re-post with the title "problem with Herbie overflow" and see what feedback you get from others that installed a Herbie.

Basically what you are saying is correct. The level in the skimmer section which feeds into the return pump section is mostly fixed by an acrylic plate that has overflow to the return section. So that level doesn't change when the return section is at normal to low level. It is the return pump section where the ATO is located that fluctuates after a power outage.

It "kind of" feels to me that the pump and gate valve get matched for flow. So if the pump return section is an inch lower or higher, it stays balanced. So if the pump turns off for a few seconds, the return pump section goes a little higher because there is still return flow from the tank, but no flow leaving the sump. The pump turns back on, and the flow is matched to the gate valve and it wants to stay at that new level. The ATO alarms because the return section has a high level, but can't do anything to correct this.

I kind of feel that there should be some kind of feedback mechanism in place to maintain balance. So even if the example above is true, then eventually the combination of high return pump section level would cause the pump to put out slightly more flow as the intake pressure is a tiny bit higher to the pump (due to elevation), and the display would have a slightly lower level, as some of the water that was previously in the display tank is now in the sump, and thus the flow through the gate valve would be slightly less due really small level decrease in the main tank.

I was wondering if the return pump speed was getting reset after a power blip, but I checked it today, and it seems to go right back to where it was before it lost power. Over the course of this year, the Sicce app says I have had power outages 9 times. AND they all seem to happen when I am at work lol.

 

[rhitee93]

I am not an expert in pumping systems. However, I'll pretend to be one for a minute to give your post a bump.

If I were in your situation, I would increase the pump flow a little and then the gate valve again (it will need to be more open) until it was balanced again.

What your describing is what us EE types call an overdamped response. Usually that means you need more gain. Increasing flow might do that.

 

[PharmrJohn]

I'm just spitballing here, but do you think it might be something as simple as reevaluating your return pump flow level? Perhaps modify it so that it matches EXACTLY to the level in the tank required for the overflow to actually work? So that, in the absence of your return pump, the level of the tank would  immediately drop down to not giving the overflow ANYTHING to direct to the sump?

 

[dR3ws3r]

I am not an expert in pumping systems. However, I'll pretend to be one for a minute to give your post a bump.

If I were in your situation, I would increase the pump flow a little and then the gate valve again (it will need to be more open) until it was balanced again.

What your describing is what us EE types call an overdamped response. Usually that means you need more gain. Increasing flow might do that.

I'm an ME, but with a controls background. I totally get it. Worth a shot. I never really measured my actual outlet flow. Maybe this would be a good time to estimate that to see if I am in the ballpark of say 3-4 turnovers an hour. I just went off the pump flow curve.

 

[rhitee93]

I'm an ME, but with a controls background.

Well now that's a rare bird. Let me know if you try it. My curiosity is up!

 

[dR3ws3r]

Well now that's a rare bird. Let me know if you try it. My curiosity is up!

I need to hook a valve actuator up to the gate valve and program a PI controller to it. Talk about overkill.

 

[Asm481]

I don't do herbie's, I run a durso and put up with noise. Sounds to me like you already figured what the problem is, your return exactly matches your drain. Doesn't your setup have a second drain line? Maybe the level of that needs adjustment assuming your weir doesn't change after a shut down. How big is your overflow area. Is that level fluctuating?

 

[Dom]

Basically what you are saying is correct. The level in the skimmer section which feeds into the return pump section is mostly fixed by an acrylic plate that has overflow to the return section. So that level doesn't change when the return section is at normal to low level. It is the return pump section where the ATO is located that fluctuates after a power outage.

It "kind of" feels to me that the pump and gate valve get matched for flow. So if the pump return section is an inch lower or higher, it stays balanced. So if the pump turns off for a few seconds, the return pump section goes a little higher because there is still return flow from the tank, but no flow leaving the sump. The pump turns back on, and the flow is matched to the gate valve and it wants to stay at that new level. The ATO alarms because the return section has a high level, but can't do anything to correct this.

I kind of feel that there should be some kind of feedback mechanism in place to maintain balance. So even if the example above is true, then eventually the combination of high return pump section level would cause the pump to put out slightly more flow as the intake pressure is a tiny bit higher to the pump (due to elevation), and the display would have a slightly lower level, as some of the water that was previously in the display tank is now in the sump, and thus the flow through the gate valve would be slightly less due really small level decrease in the main tank.

I was wondering if the return pump speed was getting reset after a power blip, but I checked it today, and it seems to go right back to where it was before it lost power. Over the course of this year, the Sicce app says I have had power outages 9 times. AND they all seem to happen when I am at work lol.

Can you post some pictures?

 

[Dom]

Basically what you are saying is correct. The level in the skimmer section which feeds into the return pump section is mostly fixed by an acrylic plate that has overflow to the return section. So that level doesn't change when the return section is at normal to low level. It is the return pump section where the ATO is located that fluctuates after a power outage.

It "kind of" feels to me that the pump and gate valve get matched for flow. So if the pump return section is an inch lower or higher, it stays balanced. So if the pump turns off for a few seconds, the return pump section goes a little higher because there is still return flow from the tank, but no flow leaving the sump. The pump turns back on, and the flow is matched to the gate valve and it wants to stay at that new level. The ATO alarms because the return section has a high level, but can't do anything to correct this.

I kind of feel that there should be some kind of feedback mechanism in place to maintain balance. So even if the example above is true, then eventually the combination of high return pump section level would cause the pump to put out slightly more flow as the intake pressure is a tiny bit higher to the pump (due to elevation), and the display would have a slightly lower level, as some of the water that was previously in the display tank is now in the sump, and thus the flow through the gate valve would be slightly less due really small level decrease in the main tank.

I was wondering if the return pump speed was getting reset after a power blip, but I checked it today, and it seems to go right back to where it was before it lost power. Over the course of this year, the Sicce app says I have had power outages 9 times. AND they all seem to happen when I am at work lol.

I once put together a sump whose ATO float was in the return chamber. I can't explain why, but, it just was impossible for me to get the level dialed in.

It almost sounds as though there isn't enough water volume in the tank.

 

[dR3ws3r]

Can you post some pictures?

I’ll post some tomorrow. Lights are out

 

[dR3ws3r]

This is a herbie system as "borrowed" from the BRS sight.

Here you can see the emergency drain (middle right), and the main drain (middle left), that has a float on top. The main drain is actually a pipe with slits cut out of the sides of it. You can kind of see the top of the main drain line in the next photo

Here is a view of the main plumbing:

The 4 vertical pipes from left to right.

Left, is pump exit flow to the left side of tank.
Middle left, main drain with gate valve
Middle Right, emergency line that goes straight to the return pump chamber
Right, is the pump exit flow to the right side of the tank.

Just a photo of the main return line going into a chamber that leads to the filter socks. Flow goes from back left corner, forward. I currently have both heaters in the same chamber as the main return line from the tank.

This is the return pump chamber. The valve on the right is a right after the return pump. The ATO is hard to see but is on the back right wall. You can see the ATO fill line at the top right, and the emergency drain pipe on the back middle left. This is where level goes out of whack when the power blips. I have the ATO set about 1" below the combs. So around 6". Perhaps I should change that? I am not sure . If the level isn't below the combs though, they probably won't serve their purpose of helping with bubbles from the skimmer chamber. I don't like this sump layout as working in the return pump chamber is very difficult. I would prefer a simple left to right flow pattern, not this circular back left, to front left, to front right to back right. And the sump has a 15 gallon ATO built into it that I am currently not using. I have a separate external ATO reservoir on the right of the tank.

This is the sump view from the front. The level stays at 7" in here as long as the water level is close to balance. On the back left, you can see the comb which overflows from the Skimmer chamber to the return pump chamber. So as long as the water in the return chamber doesn't go over the comb, the skimmer chamber stays at 7". The flow from the last filter sock comes in from the lower left, just past the temperature probe.