Water line / freeboard(?)

ctripi · 03/21/2018, 09:51 PM

Planning a rimless cube with a low profile/ghost overflow. How far below the rim should I plan the water line below the rim.
Tank volume is gonna be in 40-50 range, sump flow thru in the 250-300gph range and it’s a 16” wide overflow (almost coast to coast) with 1” weir teeth.
Gonna use 2 mp40’s for sps levels of flow.
Thoughts?

thegrun · 03/21/2018, 10:11 PM

That depends on how much water you want on the floor during the next earthquake! Here in California I really prefer a euro-braced tank for just that reason. The euro-brace will not stop all the water but they help significantly in reducing the amount of water that escapes during an earthquake. All that water has a big time potential for causing a fire when it hits your electrical equipment below.
As to your question I would keep it at least 1" below the surface. That 1" also seems to keep most of the snails from climbing out of your tank.

mcgyvr · 03/22/2018, 04:58 AM

IMO 1.25" is perfect on a rimless..

The turbulence from a powerhead can easily push the water up 3/4-1" or more

jmm · 03/22/2018, 08:46 AM

I liked the look of frameless aquariums and bought one. The water level was about one inch below the edge. Water would overflow the edge when I (carefully) cleaned the glass with magnets or scrapers. Fish jumped out. I had to be careful with the return to make sure it didn't cause a wave to overflow. I put a mesh top on to keep the fish from jumping. It looked no better than a framed tank. The frame on the top was just as distracting as the frame on a conventional tank. So, I took it off and kept only corals in the tank. They don't jump.

So I designed my own rimless tank. I made it a little taller than I had originally planned and put the overflow lower. There is about four and a half inches of glass above the water line. I don't need a top to keep the fish in. I can have all the surface turbulence I want with no danger of drips overflowing. And I can park my magnets above the water line in a back corner where no coralline algae can grow on them. I really like the way it looks and works.

Originally skeptical, the aquarium store and tank builders liked it enough to build several more than way since then.

Volcmreefer · 03/22/2018, 11:34 AM

I agree with 1.25”.

ssky · 03/22/2018, 02:44 PM

I say go 1 5/8 of an inch. Has to be perfect.

03/21/2018, 09:51 PM	#1
ctripi Registered Member Join Date: Feb 2007 Location: Easy bay , ca Posts: 677	Water line / freeboard(?) Planning a rimless cube with a low profile/ghost overflow. How far below the rim should I plan the water line below the rim. Tank volume is gonna be in 40-50 range, sump flow thru in the 250-300gph range and it’s a 16” wide overflow (almost coast to coast) with 1” weir teeth. Gonna use 2 mp40’s for sps levels of flow. Thoughts?

03/22/2018, 04:58 AM	#3
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	IMO 1.25" is perfect on a rimless.. The turbulence from a powerhead can easily push the water up 3/4-1" or more __________________ Who me?

03/21/2018, 10:11 PM	#2
thegrun Registered Member Join Date: Dec 2008 Location: Garden Grove, Ca Posts: 17,023	That depends on how much water you want on the floor during the next earthquake! Here in California I really prefer a euro-braced tank for just that reason. The euro-brace will not stop all the water but they help significantly in reducing the amount of water that escapes during an earthquake. All that water has a big time potential for causing a fire when it hits your electrical equipment below. As to your question I would keep it at least 1" below the surface. That 1" also seems to keep most of the snails from climbing out of your tank.

03/22/2018, 08:46 AM	#4
jmm Registered Member Join Date: Jan 2015 Location: Dallas, TX Posts: 569	I liked the look of frameless aquariums and bought one. The water level was about one inch below the edge. Water would overflow the edge when I (carefully) cleaned the glass with magnets or scrapers. Fish jumped out. I had to be careful with the return to make sure it didn't cause a wave to overflow. I put a mesh top on to keep the fish from jumping. It looked no better than a framed tank. The frame on the top was just as distracting as the frame on a conventional tank. So, I took it off and kept only corals in the tank. They don't jump. So I designed my own rimless tank. I made it a little taller than I had originally planned and put the overflow lower. There is about four and a half inches of glass above the water line. I don't need a top to keep the fish in. I can have all the surface turbulence I want with no danger of drips overflowing. And I can park my magnets above the water line in a back corner where no coralline algae can grow on them. I really like the way it looks and works. Originally skeptical, the aquarium store and tank builders liked it enough to build several more than way since then.

03/22/2018, 11:34 AM	#5
Volcmreefer Registered Member Join Date: Mar 2006 Location: Milton, FL Posts: 346	I agree with 1.25”.

03/22/2018, 02:44 PM	#6
ssky Registered Member Join Date: Jan 2017 Posts: 115	I say go 1 5/8 of an inch. Has to be perfect.