Baffle spacing
- Thread starter Timbor
- Start date
AZDesertRat
In Memoriam
My sump is a 30G long and I placed the baffles 2" on centers apart so they ended up about 1.75" apart clear. Its just enough to get a cleaning magnet or brush between them if I am so inclined.
dngspot
Premium Member
The first question to ask is how big of a pump will you be using to return water to the tank, the bigger the pump the faster the flow through the refigium. You will also want to know how much of the actual refigium you are willing to sacrifice to baffle spacing. I have a 55 gallon tank baffled as I described and run a 1700 gph pump for return. I wanted a large refigium and suffered the micro bubble problem you are asking about. After the bubble caulpera took off, the problem was over due to the caulpera slowing the bubbles. I have built another 20 gallon for a friend and he uses a 400 gph pump with absolutely no bubble problem at all.
I silicone the first baffle from the input side then I use 1 inch blocks, I got from the acrylic shop, for stands for the next high baffle. It is siliconed in next. Then I install the next and work my way down the tank. You will not need to silicone both sides of the baffles.
I silicone the first baffle from the input side then I use 1 inch blocks, I got from the acrylic shop, for stands for the next high baffle. It is siliconed in next. Then I install the next and work my way down the tank. You will not need to silicone both sides of the baffles.
Timbor
New member
Yeah, I am not using a very high flow sump. The sump is a 30 gal, and the main tank is a 35. I will be having about 200GPH flowing in the sump. My return pump is an eheim 1250.
I plan on using only 2 baffles on the skimmer side, then just a divider between the fuge and the return. Flow through the sump will be right to left: skimmer --> fuge --> return
I think I will space the baffles about 1.5" or so.
Tim
I plan on using only 2 baffles on the skimmer side, then just a divider between the fuge and the return. Flow through the sump will be right to left: skimmer --> fuge --> return
I think I will space the baffles about 1.5" or so.
Tim
CoolUsername
New member
Baffle (Bubble trap) design ideas
Baffle (Bubble trap) design ideas
Here are a couple of design ideas for a bubble trap baffle. These sump diagrams might not representative your specific sump setup, but the principles of the bubble traps within them are useful for any configuration.
First principle: The first chamber has equipment or processes that generate bubbles, most likely micro bubbles. This is either from a protein skimmer outlet or the overflow drain from the display. It is desired to keep these micro bubbles from entering chamber 2. Falling over the weir (baffle 4) will generate some more bubbles and we would like to keep these out of chamber 3 since our main return pump usually sits here and will return these little nuisances back to the display tank where they will scatter our light, potentially bother our corals, and make out water look grainy.
Second: Ideally we would like to minimize the space taken up by the baffles. These spaces take away from our potentially larger refugiums and top off reservoir limiting what sized pumps and skimmers we can fit in out sump.
Third: Sumps will get dirty. In fact we kind of hope they do. The more algae we grow in the sump, the less likely algae will grow in the main tank. There are a fixed amount of algae feeding nutrients. However we do need to clean things once in a while. The space between baffles should be sufficient to allow a glass cleaning brush to fit between.
Here is your typical sump configuration.
The sump water height is determined by the height of weir #4. Most people place the baffles 1, 2, & 3 equidistant from each other. At least I haven’t seen any one do it different.
Bubble traps are created from a body of water whose downward flow rate is moving slower than the rate at which the microbubbles rise. This allows the bubbles to escape. The first chamber coupled with baffle 1 is the fist bubble trap. And the most effective one at that. Most of the bubbles will be filtered here. The second bubble trap is the water column between baffles 2 and 3. Making the distance between these two baffles as great as possible will make this trap more effective. It is important to note that the distance between baffles 1 and 2 is not significant to the traps function. Making it smaller will increase the upward rate of flow. Who cares how fast we bring the water back up to the surface. It only needs to be wide enough to clean periodically.
The second diagram includes these optimizations on the first design. I have moved baffle #2 to the left to slow down the downward rate of flow. This will filter more microbubbles. Note that the distance between baffles 1 and 3 is identical. Which satisfies the second design principle above or at least it remains the same while improving on principle 1.
It would be nice to make the space between baffles 1 and 2 minimal like ½ inch or even ¼. Maybe someone has an idea about making removable baffles. Really only baffles #2 and #4 have to be fixed. Compartment 2 is usually houses a deep sand bed and would need sturdy permanent walls to support it. #4 also has a lot of water pressure against it. It needs to be permanent. You could conceivably make a slot for baffles 1, 2, and 5. That would be cool. Easy to clean and maximize space. Anyone have any ideas for removable baffles. The rest of these don't have to be perfectly water tight. They are really only directing water flow to force bubbles to the surface.
Baffle (Bubble trap) design ideas
Here are a couple of design ideas for a bubble trap baffle. These sump diagrams might not representative your specific sump setup, but the principles of the bubble traps within them are useful for any configuration.
First principle: The first chamber has equipment or processes that generate bubbles, most likely micro bubbles. This is either from a protein skimmer outlet or the overflow drain from the display. It is desired to keep these micro bubbles from entering chamber 2. Falling over the weir (baffle 4) will generate some more bubbles and we would like to keep these out of chamber 3 since our main return pump usually sits here and will return these little nuisances back to the display tank where they will scatter our light, potentially bother our corals, and make out water look grainy.
Second: Ideally we would like to minimize the space taken up by the baffles. These spaces take away from our potentially larger refugiums and top off reservoir limiting what sized pumps and skimmers we can fit in out sump.
Third: Sumps will get dirty. In fact we kind of hope they do. The more algae we grow in the sump, the less likely algae will grow in the main tank. There are a fixed amount of algae feeding nutrients. However we do need to clean things once in a while. The space between baffles should be sufficient to allow a glass cleaning brush to fit between.
Here is your typical sump configuration.
The sump water height is determined by the height of weir #4. Most people place the baffles 1, 2, & 3 equidistant from each other. At least I haven’t seen any one do it different.
Bubble traps are created from a body of water whose downward flow rate is moving slower than the rate at which the microbubbles rise. This allows the bubbles to escape. The first chamber coupled with baffle 1 is the fist bubble trap. And the most effective one at that. Most of the bubbles will be filtered here. The second bubble trap is the water column between baffles 2 and 3. Making the distance between these two baffles as great as possible will make this trap more effective. It is important to note that the distance between baffles 1 and 2 is not significant to the traps function. Making it smaller will increase the upward rate of flow. Who cares how fast we bring the water back up to the surface. It only needs to be wide enough to clean periodically.
The second diagram includes these optimizations on the first design. I have moved baffle #2 to the left to slow down the downward rate of flow. This will filter more microbubbles. Note that the distance between baffles 1 and 3 is identical. Which satisfies the second design principle above or at least it remains the same while improving on principle 1.
It would be nice to make the space between baffles 1 and 2 minimal like ½ inch or even ¼. Maybe someone has an idea about making removable baffles. Really only baffles #2 and #4 have to be fixed. Compartment 2 is usually houses a deep sand bed and would need sturdy permanent walls to support it. #4 also has a lot of water pressure against it. It needs to be permanent. You could conceivably make a slot for baffles 1, 2, and 5. That would be cool. Easy to clean and maximize space. Anyone have any ideas for removable baffles. The rest of these don't have to be perfectly water tight. They are really only directing water flow to force bubbles to the surface.
dngspot
Premium Member
I like the principle behind the diagram above and the points that are being made are valid. I considered building my first sump in the same manner. The problem I would have had is, I wanted a deep sand bed and in compartment 2 the sand would have eventually plugged up the 3rd elevated baffle on the intake side. Not a good thing in my case. Plugged baffles mean water on my floor. I also keep my water higher than baffle 4, to keep the water fall from making bubbles.
Pbrown3701
New member
the closer together the baffles are, the higher the velocity of the water through and the less likely they are to remove the microbubbles - as you mentioned earlier in your post.
Are you planning to use an auto top off system with that small return pump compartment?
Are you planning to use an auto top off system with that small return pump compartment?
dngspot
Premium Member
It is true the closer the baffles are the less efficient they are at bubble elimination. With a small flow pump, smaller than 1000 gph, there will be a slow movement through the traps at 1 inch by 12 wide and 12 inches deep, enough that by the time they get to the pump the water will be clear. This has been witnessed time and again.
Timbor
New member
Here is a schematic of what I was planning on doing with my sump:
As you can see, my current design only uses 3 baffles - 2 on the skimmer side, and one on the return side. The baffle on the return side will be 3" shorter than the other side. There are two reasons why I plan on doing this:
First, it will slow the rate of water drop in the sump, since that 3" will be shared with the refugium. It would be a safeguard in the case of me forgetting to top off the water (I don't plan on neglecting it, but just in case).
Also, I plan on making some sort of box out of eggcrate to hold carbon or other media that will be made to rest on the baffle on the return side.
I think with the low flow, and the media box in place, it would prevent microbubbles from reaching the display tank.
Good idea? Bad idea?
Tim
As you can see, my current design only uses 3 baffles - 2 on the skimmer side, and one on the return side. The baffle on the return side will be 3" shorter than the other side. There are two reasons why I plan on doing this:
First, it will slow the rate of water drop in the sump, since that 3" will be shared with the refugium. It would be a safeguard in the case of me forgetting to top off the water (I don't plan on neglecting it, but just in case).
Also, I plan on making some sort of box out of eggcrate to hold carbon or other media that will be made to rest on the baffle on the return side.
I think with the low flow, and the media box in place, it would prevent microbubbles from reaching the display tank.
Good idea? Bad idea?
Tim
AZDesertRat
In Memoriam
Are you planning an autotopoff? That is an extremely small return pump section and will require daily water additions if not.
CoolUsername
New member
Deep Sand Bed
Deep Sand Bed
I agree about the sand bed. The diagrams were simplified and don't show how you would incorporate one. I did the following:
This closely resembles what I have done. I actually have a plunum with 4.5 inch deep bed on top.
I also added the T-support since my weir was bowing significantly.
Deep Sand Bed
I agree about the sand bed. The diagrams were simplified and don't show how you would incorporate one. I did the following:
This closely resembles what I have done. I actually have a plunum with 4.5 inch deep bed on top.
I also added the T-support since my weir was bowing significantly.
CoolUsername
New member
Yes, the closer the baffles the higher velocity, but for the baffles that create an upward current you won't get any bubble removed no matter how slow your current. What we are trying to do is - in a given set of space - create the slowest downward flows. This accentuates bubble removal. So by moving the center baffle over (leaving the outer baffles in place) we get a better bubble trap in the same amount of sump space.
CoolUsername
New member
I have a 900 GPH flow rate with a 2 inch wide 8 inch deep downward baffle and I still get microbubbles in my refugium. Not a lot but enough to notice.
CoolUsername
New member
<a href=showthread.php?s=&postid=7755074#post7755074 target=_blank>Originally posted</a> by Timbor
Here is a schematic of what I was planning on doing with my sump:
As you can see, my current design only uses 3 baffles - 2 on the skimmer side, and one on the return side. The baffle on the return side will be 3" shorter than the other side. There are two reasons why I plan on doing this:
First, it will slow the rate of water drop in the sump, since that 3" will be shared with the refugium. It would be a safeguard in the case of me forgetting to top off the water (I don't plan on neglecting it, but just in case).
Also, I plan on making some sort of box out of eggcrate to hold carbon or other media that will be made to rest on the baffle on the return side.
I think with the low flow, and the media box in place, it would prevent microbubbles from reaching the display tank.
Good idea? Bad idea?
Tim
The media chamber is a nice idea. Especially if you make it media optional.
About the second weir. I you are planning on running with a nominal water level that is higher than this second weir you won't sheild your refugium critters (macros, snails, fish etc) from access to the return pump intake. They can swim, climb, flow right over. Maybe you could put up some sort of screen like a breeder divider on top of the second weir. This would let the water through but keep your critters safe.
CoolUsername
New member
My return pump section nominally holds 4 gallons. I typically have to top off daily as you suggested. This is especially true in Arizona with our dry air and since I'm using evap fans in place of a chiller. I loose about 2 gallons a day. Total system is 130 gallons. I have been planning an auto top off from day one. I just haven't yet implemented that yet. I recently installed the RO unit. It will be soon.
Timbor
New member
Currently, I won't be using an auto top-off. With what I plan to do, the 3" of water above the last weir would be the first to evaporate. In that case, there would be about 11.2L that would be evaporated before the chamber water level drops below the weir. The return chamber (below the top of the weir) will hold 12.7*30.48*25.4" = 9.8L, so there is actually going to be more water above the wier to be evaporated.
The total water that could be evaporated would be roughly 5 gallons before the return runs dry. In a system that has about 50-60 gallons total, 5 gallons would be way to much to let evaporate. I don't think a larger return section will change much. That is why I decided to make the last weir shorter.
The concept of the media box that sits on the last weir is twofold. It will be able to hold chemical media, such as carbon, but it will also act as a screen to keep the refugium inhabitants in their place.
CoolUsername, I like your idea to use some sort of breeder screen to keep the inhabitants in place as well. I would probably employ that as a second safeguard.
Tim
CoolUsername
New member
Yes, I agree with you about letting 5 gallons evaporate. That would drop your salinity about .002 points (1.025 to 1.023) for a 60 gallon system. This kind of salinity swing would put some stress on your inhabitants, but i t might save your pump. I guess the real key is not forget to top off daily or better yet implement an auto topoff!
I used the calculator:
http://www.saltyzoo.com/SaltyCalcs/EvapSalinityCalc.php
I used the calculator:
http://www.saltyzoo.com/SaltyCalcs/EvapSalinityCalc.php
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