Paying attention to the small details

[authentic]

My herbie overflow was starting to gurgle, so I adjusted my gate valve to slow the return..took a couple of adjustments to stabilize it.my first thought is what caused the change.most probably my return pump needs cleaning but I could put that off for awhile ,what I didn't think of was the effect on my salinity.my ato had to add more water over the couple of days I was adjusting the valve.being that I don't test for salinity often I didn't notice the change. My salinity dropped from 1.026 to about 1.023 my tank is predominantly sps .everything is fine but the small things really need to be paid attention to.

 

[Alfrareef]

I’m not sure if I understand the relationship between reducing return flow and ATO consumption increase. The tank+sump water volume it’s the same and you didn’t have a tank overflow.

 

[3mm3]

I’m not sure if I understand the relationship between reducing return flow and ATO consumption increase. The tank+sump water volume it’s the same and you didn’t have a tank overflow.

Changing flow rates through the system affects the water level in the sump return pump area. You will either increase or decrease salinity depending on what flow changes where made. If I increase my return pump speed my auto top off will add water to compensate.

 

[Alfrareef]

Changing flow rates through the system affects the water level in the sump return pump area. You will either increase or decrease salinity depending on what flow changes where made. If I increase my return pump speed my auto top off will add water to compensate.

Yes, but after stabilizing shouldn’t the level be the same? After all the water comes down to the sump...

 

[Randy Holmes-Farley Verified Community Expert]

Yes, but after stabilizing shouldn’t the level be the same? After all the water comes down to the sump...

If you change the flow rate through a system with an overflow, higher flow will leave more water in the area behind the overflow (waiting to flow over it). Depending on the nature of the overflow dimensions, etc., the effect can be quite significant.,

 

[Flippers4pups]

Yep, if I increase my flow to the DT, the sump level will drop enough for the ATO to kick on till it fills back up to the float switch. In my system, it's not a big concern, but In a smaller system it could be significant.

 

[authentic]

My system is 140 gal but I adjusted the flow over a few days causing the drop,glad I caught it.shut if my auto will add SW until it's back to 1.026,,,always take things slow

 

[Flippers4pups]

Yep, ATO off for water change as well. Just remember to turn it back on after!

 

[3mm3]

Yep, if I increase my flow to the DT, the sump level will drop enough for the ATO to kick on till it fills back up to the float switch. In my system, it's not a big concern, but In a smaller system it could be significant.

Very true!

 

[Alfrareef]

Thank you Sirs! I think I’ve understood.
The overflow act as a buffer.

 

[Geebs19]

It’s always something haha.

 

[Dennis Cartier]

Along the same lines as the OP, but for a different cause, I experienced the following. I recently installed an Alkatronic alkalinity monitor/controller. While getting familiar with the unit, and getting my dosing 2 part/Kalk dialed in, I was paying close attention the graph display of the Alkatronic. I have the unit testing every 4 hours at the moment. Anyway, I noticed a rapid decline in my tanks alkalinity one day while at work. I had just trimmed the giant chaeto beachball in my fuge as my SPS frags growth was stalled, so I attributed the sudden increase in alkalinity consumption to the lower competition for nitrate from the fuge. I had been struggling with balancing the H380's insane growth, with my need for some nutrients for my frags to grow.

When I got home from work and looked at my tank, the reason for the alk drop became instantly clear. My sump was about 2" from the top rim, which is about 4" higher than normal. My ATO was running, even though the float valve was under water. The ATO had stuck on, and was likely running all day (6 RPM Masterflex), and had lowered the salinity from 1.026 to 1.024. This was the cause of the downward slide I had observed in the Alkatronic graph. Doh.

Once I unstuck the float valve, the ATO shut off and has remained off for several days, and my alkalinity has crept slowly back up. I trimmed back my chaeto further and reduced the lighting period and my NO3 has risen to 1.0 ppm from 0.2 ppm and alk graph again started on a much slower decent. This time for the right reason.

Dennis