High Tide Low Tide IN DISPLAY TANK

[hexcolor reef]

I noticed in my main display tank the water levels drops and rises through out the day. More so when its warmer/higher humidity the water level drops. Cooler temps the water level rises. It appears this way any how. I did some googling and didn't find anything. Is this a normal thing has anyone else witnessed this happening?

 

[Reefering1]

Does this setup have a overflow and sump?

 

[hexcolor reef]

Does this setup have a overflow and sump?

yes, today I stood and watched it happen, thought I had a leak somewhere

 

[Reefering1]

How many drain pipes? A display with a free draining overflow should not have fluctuating water level. Its possible that the main drain is somewhat blocked and emergency is going in and out of full siphon. Or maybe the return pump is fluctuating speed. Do the drains make noise? Is the water level in return chamber steady or rising/ falling with the "tide"?

 

[hexcolor reef]

How many drain pipes? A display with a free draining overflow should not have fluctuating water level. Its possible that the main drain is somewhat blocked and emergency is going in and out of full siphon. Or maybe the return pump is fluctuating speed. Do the drains make noise? Is the water level in return chamber steady or rising/ falling with the "tide"?

no noise from the drains. I do believe the return could be fluctuating. it's the one I'm constantly adjusting when it happens. the draining over flow is clear, I just did a quick service to it yesterday.

 

[Reefering1]

Pics of plumbing and return set up