40B Sump Baffles, water level questions

[Brom]

Hi thanks for your time,

I ordered 4 baffles from the local glass shop after some measuring with my final stand height and the act of removing my skimmer lid and cup. Therefore, the maximum height I can have my chamber 1 (socks and skimmer) is 12" height with the skimmer on an approximately 5-1/2" stand. After the first 12" baffle I had 3 identical 11" baffles cut too. I read a little about over-under-over vs the opposite and arrived at this intended bubble trap setup. I am running a separate fuge in a 29 situated above my DT to flow into it so I am hoping to have a fair bit of leeway in my return section (3) for back flow before I flow into other sections. If I went with this setup, will the return section run higher than baffles B/D? Would they run higher than A, up to C? (exaggerated height). Is there a setup where I could allow the return chamber to run higher than the skimmer section (1)? Maybe a 2 baffle design for the bubble trap, where I could use one of the 11" as an exaggerated under-flow right after A, to where the skimmer section would be the last section to fill up with backflow? Any other suggestions?

Thanks again!

 

[R.Weller]

We are using an under-over-under flow on the bubble trap & it is nice to have access to the bottom of the tank in the event that the area needs to be cleaned. I found that design in a book & thought it was clever. If you go that route, the height of the return is the center baffle. Generally, the return is the chamber with the shortest height & it’s the only chamber with variable height based on your top off strategy.

 

[Brom]

Follow up question-on the under baffle, how long do you leave the support underneath it while the silicone sets up?

 

[RocketEngineer]

You could take it out after the silicone sets. I left mine overnight.

To your original question: water only flows downhill so the levels in sections 1 and 2 will be above that of 3 no matter what. Physics.

In theory you can remove baffle B and really not impact much depending on what you plan for the middle section.

 

[RobB'z Reef]

You could take it out after the silicone sets. I left mine overnight.

To your original question: water only flows downhill so the levels in sections 1 and 2 will be above that of 3 no matter what. Physics.

In theory you can remove baffle B and really not impact much depending on what you plan for the middle section.

Walk me thru that... If we assume an equal input and output between sections 1 & 3 I would think the level of section 1 to be the highest and sections 2 & 3 to be equal. Yes water flows downhill but it also seeks it's own level. I don't see anything wrong with that design but I'm just trying to understand your perspective here.

 

[RocketEngineer]

Water only seeks level when static. The pump creates a dynamic situation which dictates physics change. When the system is running, the pump is going to be removing water from section 3 and adding it to section 1. This causes the level in 1 to rise until the amount that flows over the baffle has matched what’s coming in. The same thing happens in 2, the water level rises as water enters until it is equaled by what leaves. This movement of water only occurs because the uphill section has a higher water level than the downhill section. It’s not much of a difference, but it is a difference.

 

[RocketEngineer]

Here is a good pic of my sump while running. If you zoom in on the bubble trap left of center you will see the skimmer side baffle is taller by design. But the baffle at the pump side has water backed up behind it relative to the return section in the middle.

 

[Brom]

You could take it out after the silicone sets. I left mine overnight.

To your original question: water only flows downhill so the levels in sections 1 and 2 will be above that of 3 no matter what. Physics.

In theory you can remove baffle B and really not impact much depending on what you plan for the middle section.

Thanks to all points. Coincidentally I siliconed A C and D yesterday with pvc holding C for now. I figured on flow but I didn’t know if the pull of return can counteract. There is no firm plan for middle chamber, heaters and space for post-manifold stuffs and perhaps some fragging space. That wouldn’t get the top sheen from going weir to under? Appreciate the response!

 

[rioreef]

Personally I would put B in. For the reason you just said, skimming the top sheen

 

[Brom]

Here is a good pic of my sump while running. If you zoom in on the bubble trap left of center you will see the skimmer side baffle is taller by design. But the baffle at the pump side has water backed up behind it relative to the return section in the middle.

+1 for Legos you really are an engineer eh? And thank you this perfectly explains it to me.

 

[RobB'z Reef]

Water only seeks level when static. The pump creates a dynamic situation which dictates physics change. When the system is running, the pump is going to be removing water from section 3 and adding it to section 1. This causes the level in 1 to rise until the amount that flows over the baffle has matched what’s coming in. The same thing happens in 2, the water level rises as water enters until it is equaled by what leaves. This movement of water only occurs because the uphill section has a higher water level than the downhill section. It’s not much of a difference, but it is a difference.

Than you