A question about water levels between sump and overflow

[Idech]

I’m not having any problems, I’m just trying to understand why this happens.

Context : today I dosed a little phyto and as usual (but I forgot), my ATO sensor got somewhat covered by it and stopped working. Since this is a new system, I monitor it frequently throughout the day and the ATO level was always perfect (I have marked it with a tape so I’m sure).

Then later tonight, I started hearing water gurgling (this system is silent when well adjusted, which it was) so I knew something was off. I went to check and the ATO was fine so I looked at the overflow box and it was about an inch lower than it needs to be quiet.

Here is my question : why, when water is evaporating in the system and not being replaced, is water missing solely in the overflow, and not at all in the sump ?

Thank you !

 

[The_Paradox]

I think I follow what you’re trying to explain. If I understand it means your pump is not flowing enough to keep up with the overflow. Not sure what style overflow you have but you can either adjust the siphon drain or increase pump speed.

 

[Idech]

I think I follow what you’re trying to explain. If I understand it means your pump is not flowing enough to keep up with the overflow. Not sure what style overflow you have but you can either adjust the siphon drain or increase pump speed.

Hmmm, I don’t think that’s the cause, as everything is perfect as long as the ATO works.

What happens to your system if your ATO stops working for half a day or a day ? Where is it missing water; in the sump or in the overflow ?

 

[EeyoreIsMySpiritAnimal]

Hmmm, I don’t think that’s the cause, as everything is perfect as long as the ATO works.

What happens to your system if your ATO stops working for half a day or a day ? Where is it missing water; in the sump or in the overflow ?

If the ATO stops, your pump chamber water level will drop.

When my system does what you're describing, it means I need to adjust the valve on my primary drain by closing it slightly so more water stays in the overflow.

 

[Idech]

If the ATO stops, your pump chamber water level will drop.

When my system does what you're describing, it means I need to adjust the valve on my primary drain by closing it slightly so more water stays in the overflow.

Okay, I see. But the way I had it, it was silent. I sit right in front of it most of the day so I need it that way.

Does it matter if it’s the overflow level dropping instead ?

 

[EeyoreIsMySpiritAnimal]

Okay, I see. But the way I had it, it was silent. I sit right in front of it most of the day so I need it that way.

Does it matter if it’s the overflow level dropping instead ?

It means that it needs to be rebalanced... the return is not pumping as much water into the tank as before. You can check your return pump (maybe it's time to clean it) or turn it up (if it's adjustable). The only other option to get things balanced again is to close the drain valve a tad.

My tank will run fine (silent) for quite a while and then I need to tweek it. Just the nature of the beast.

 

[EeyoreIsMySpiritAnimal]

Does it matter if it’s the overflow dropping instead ?

And, no, this isn't a problem except for the noise...

 

[Idech]

And, no, this isn't a problem except for the noise...

Thanks ! I’ll hear the noise and fix it because it’s very annoying.

What’s the longest you’ve had without having to fiddle with the gate valve ?

This is new to me (11 days) but it seems something happens everyday that I have to adjust it again.

 

[EeyoreIsMySpiritAnimal]

Thanks ! I’ll hear the noise and fix it because it’s very annoying.

What’s the longest you’ve had without having to fiddle with the gate valve ?

This is new to me (11 days) but it seems something happens everyday that I have to adjust it again.

It depends. Several weeks sometimes.

 

[Idech]

It depends. Several weeks sometimes.

Okay, hopefully I’ll get there too !

 

[The_Paradox]

Thanks ! I’ll hear the noise and fix it because it’s very annoying.

What’s the longest you’ve had without having to fiddle with the gate valve ?

This is new to me (11 days) but it seems something happens everyday that I have to adjust it again.

I adjust valves maybe once a year per tank if not less. As for water draining out of overflow vs return chamber it’s going to cause a larger parameter swing.

 

[Idech]

I adjust valves maybe once a year per tank if not less. As for water draining out of overflow vs return chamber it’s going to cause a larger parameter swing.

You never change your pump speed, or run out of rodi, or have your ATO stop working ? Or even add or remove a powerhead, a gyre ?

As for parameter swings, the way I see it, you’ll have them either way. If the sump goes dry, you’ll have too much rodi put in and decrease your salinity. If the overflow goes dry, you won’t replace enough water and increase your salinity.

Am I right ?

 

[The_Paradox]

You never change your pump speed, or run out of rodi, or have your ATO stop working ? Or even add or remove a powerhead, a gyre ?

As for parameter swings, the way I see it, you’ll have them either way. If the sump goes dry, you’ll have too much rodi put in and decrease your salinity. If the overflow goes dry, you won’t replace enough water and increase your salinity.

Am I right ?

I open the valve to refill my ATO every week or so. As for the overflow valve and pump I don’t have to mess with them. I keep ~ 5% of the water flowing through e-drains (I use herbie style drains) and that’s enough that I don’t have to adjust barring an algae out break or something.

As for the second part of your question, as long as whatever section is lowering in use is consistant it does not really matter. The return chamber has to fluctuate due to the range for the sensor/valve. Whereas the overflow can be kept relatively static.

As an aside I have always felt that a functioning float valve and gravity system will out perform an optical sensor and pump.

 

[Idech]

Update : I’m still monitoring but increasing the pump speed by one notch seems to have solved the issue.

My ATO is being repaired so I have to top off manually and when I check, the ATO chamber is a bit lower and the overflow box looks the same.

You guys rock, thanks !