Sump microbubbles!!! HELP

[aussiefishy]

Hi all fellow aquarist:

I have a BIG problem, my tank use a Sequence Barracuda pump and the main tank has tons of microbubbles.. i have tried using various baffles, but it not worked...

i am thinking the flow is too great, however i still need the flow and i need to make it right. I already invested alot of money into this project and my livestock can't wait... please help.

I have some ideas that MIGHT work and i really need all you input, especially aquarist using pumps that is rated at about 3500 GPH up.


using the rubbermaid black TUB, dimension is 48X24X24. with 2-3 circular buckets one into another as a baffle. i would like to make the new design to be 48inch in length due to space limitation.

Cost is an issue as i have already invested over 500 in the existing sump setup..

can anyone please help me!! i need to relocate my livestock soon as i am in the middle of upgrading to a bigger tank... please help!

 

[Nautilus1]

With all those baffles I dont see how bubbles are getting into your main tank. Perhaps there is a leak that is sucking air on the intake of your barracuda.

 

[FragMaster]

I dont understand?
Are the bubbles from the return pump? A skimmer? Or simply from the
overflow in to the sump?

 

[Anonymous]

The bucket idea won't do a thing because all the flow is going over the top of each bucket. You can use that bucket idea if you have holes in the bottom of the buckets so the water can exit and the bubbles float. However, You are putting a ton of flow through that thing, and you may have to use more than one method.

For the dividers, the water should go over, and then under each successive divider. In your drawings it looks like the lower dividers are not near tall enough, the idea is to get the bubbles as close to the surface of the water as possible when the flow is going up and as low to the bottom as possible when the flow is going down.

With a long sump like that, you may be able to stop a lot of the bubbles by placing baffles at something like 4 inch intervals sticking down from the top into the water and leaving about 2-3 inches below them. As the water flows through it the bubbles will tend to rise and get caught by the baffles.


That is of course, unless there is just too much flow the bubbles are being pushed straight from the drain to the return by the force of the water.



When I installed my sump I didn't put any baffles because I didn't know where to put them. I didn't need any because I have such a deep sump the bubbles all rise to the top before running the length of the tank. But then I am only pushing abour 900 gallons an hour through it.

If all else fails one of those blue polyfilters will stop a ton of bubbles, but they have to be cleaned regularly...

 

[Anonymous]

OH, one final thing

If you make the buckets each inside of the other with holes in the bottom of them, keep the number of holes to a minimum, you want all the water to flow out the bottom, but you want the buckets to fill up to the top so that the bubbles have plenty of time to gather together and pop.

Tonight I will post a pic of the thing in the corner of my sump, I have to turn the tank off to remove it....

 

[Sponge_Bob]

Knucklehead makes a good point when he talks about the high flow rate of your pump vs the bubbles being carried by the high flow. First, why do you need sush a high flow rate??? I can not for the life of me believe that you are REALLY pushing 3500 gph into your main tank. If you do, what kind of overflow do you use, a 3" pipe?!? All jokes aside, what is your head on this setup and what is the REAL flow rate with that head?

Anyway, the problem should not be so hard to solve if your baffle placement is right. Here's a quick drawing that I've posted many times on this board and it has helped some people.

With this baffle placement, you get the following:

1. Bubbles are not passing through the first set of baffles and the water level is stable. Please note that the flow is under-over-under.

2. The second section of the sump is the largest one. Water level is also constant in that section.

3. Third section hosts the return pum and the baffles before it are over-under-over. The water level in that section will vary depending on skimming removal water and evaporation. So it acts like a gauge as to how much water was lost and should be replaced.

Depending on how much bubbles are made by your overflow return, some skimmers might malfunction because of that. You may want to move your skimmer into the second section.

HTH

 

[Anonymous]

As spongebob pointed out, you do not have enough "over under" to reduce bubbles. You must make the water travel a larger column that you have for them to be able to "pop".

Also having a larger area in between like sb has reduces them greatly.

 

[aussiefishy]

Thank you for all your help!

1. i can literally see the bubbles pass through all baffles and end up being pull into the intake of the pump.

2. at the last baffle before the intake, i can literally see the flow (water movement) being pull by the pump.

3. a barracuda is about 3800 GPH at 0 head?... so my assumptyion on flow is inaccuarate.. maybe 2000GPH accounted for head loss is more right.

4. i tried putted foam on the first couple baffles and the effects was water level rise and minimum benefit... the pump is so powerful it pulls the bubbles through foam and baffles and end up suck back up to intake. that is the problem...

5. if the under over under baffles has to be so high, if i have a power failure my sump will be overflowed... how to solve?

6. Please help me decide whether i should use the rubbermaid bucket or design a brand new sump... 8O

 

[Anonymous]

Thank you for all your help!

1. i can literally see the bubbles pass through all baffles and end up being pull into the intake of the pump.

2. at the last baffle before the intake, i can literally see the flow (water movement) being pull by the pump.

3. a barracuda is about 3800 GPH at 0 head?... so my assumptyion on flow is inaccuarate.. maybe 2000GPH accounted for head loss is more right.

4. i tried putted foam on the first couple baffles and the effects was water level rise and minimum benefit... the pump is so powerful it pulls the bubbles through foam and baffles and end up suck back up to intake. that is the problem...

5. if the under over under baffles has to be so high, if i have a power failure my sump will be overflowed... how to solve?

6. Please help me decide whether i should use the rubbermaid bucket or design a brand new sump... 8O

1-4 sounds like too much flow in the sump. I would cut down the gph a bit. It isnt supposed to be a cyclone, but more of a "calm" area. Its a refugium, not a cyclonic aeration area.

5. Make it so the level in your tank (the intake level/pump head/overflow) is mounted such a height and the amount of baffle height is equal or lesser than the volume of water that can be taken from the tank...hard to decribe...hope you undertand what I mean. So that if you have a pump failure for return, the amount of water that can possibly be sucked from the tank will not overflow the sump...

6. start over! lol...pain int the ass, but if yoiu want a neat, clean organized sump, its the best way. But again, i am kinda neat freak with that stuff. Rubbermaid works fine, however.

 

[Anonymous]

I would like to point out that minimizing the amount of water that will fall to the sump after the pumps shut off is one way of getting a higher water level in the sump.

Mine brings the water level up about 1 inch in a 45 tall sump tank.

 

[FragMaster]

Ball valves on both sides. Problem solved.

 

[Anonymous]

Here is a picture of my DIY bubble trap.

It actually worked very well when my sump was a 20 tall under my stand.

Its a piece of 6 inch PVC, in the middle of it there is a piece of clear acrylic with a bunch of 3/8 inch holes in it. then there are slots cut around the bottom of it.


the water would fall into it and go out the bottom, the slots and plate with holes in it made the bubbles get together and pop.

The clear plastic tube is there because when I stick my arm in the main tank it causes the overflows to siphon completely and that makes a bit of a splash in the sump which splashed just a bit and made me think the sump tank was leaking (oh horrors).

 

[trido]

Sponge Bob. A barracuda pump will give you 3500GPH with 6 foot of head. It is rated at 4500GPH with 0 head. 3780 at 4" head. And so forth.
Aussiefishy, why do you want to run that much through your sump. Can your overflows really handle that much? Can you buy a smaller pump and use the barracuda as a closed loop? Bubble problem dissapears.

 

[Sponge_Bob]

With the information supplied by Trido, it's clear that your pump is way over sized for the job, unless you are pushing water from the basement up to the second floor...and even then, it seems like your pump is way too powerful. With that kind of a flow rate, I guess this is a centrifugal pump. You COULD, with GREAT caution, put a gate valve, NOT a BALL valve at the exit of the pump and try to limit the flow rate. A gate valve will provide you with a much more accurate fine tuning of the flow rate than a ball valve would. The danger with doing that is that your pump may start to "cavitate". If the pump starts to cavitate, you will hear a "rock tumbling" like noise comming from it. Open the valve as quickly as you can or shut down the pump at once. Cavitation is the sudden formation and collapse of low-pressure bubbles in liquids by means of mechanical forces, such as those resulting from rotation of a marine propeller. It will destroy your impeller. That's the main disadvantage of a centrifugal pump. They are very powerful but you can hardly reduce the flow rate without risking of making your pump cavitate. Also, please consider that the pressure between the valve and the exit of the pump will be greater and might require a more resistant tubing than a non-restricted flow would.

Enough theory on the mechanic of fluids. HTH a bit.

 

[aussiefishy]

Thanks for all you help!! i really appreciate it!

let me give you more info on this setup.

1. the barracuda is used to pump from basement to main floor. the sump and pump is 4 feet up above the basement floor and total head is about 10 feet (from sump to top of tank)

2. There is a close loop (a velocity T4) above 1500 GPH

3. The bubbles are caused by the pump sucking/pulling water too fast through baffles.

4. I have a 2 inch overflow hole that can handle the flow quite well. (if it cannot handle the flow, the overflow would overfill with water and there should be little or no bubble flow out into the sump in the first place.)

5. I primarily keep SPS corals, so flow is improtant to me, and i bought the barracuda for this application and dedicated to change the SUMP to accomodate the flow it needs... any suggestion as to how big a sump for the pump should eb and how it should be designed?? please help! 8O

 

[aussiefishy]

And if i have to reduce the flow to accomdate for bubbles that kind of defeat the purpose of my investment into this pump... so is there any ideas out there that can eliminate microubbles and have a high flow? what is the sump volume and size.?? 8O

 

[trido]

O.K. Did some looking. The T-4 is rated at 1250GPH at 3' of head. The Barracuda should be giving you about 2700GPH at 10 of head. I am in the process of designing my pump system for my 120. So im researching all of this info. By the way. How big is your display tank?
The general rule of thumb is to only run through your sump what your skimmer can run through in any given hour. Scientificly, the skimmer will function most efficiently if it circulates the total volume of tank water 10 times in a 12 hour period. So for my 120. Only 120 gallons an hour through the skimmer. My skimmer has a sedra 5000 rated at 500GPH. With a needle wheel and a venturi my guess is that is will only pull 30% of that water capacity at 150GPH. My skimmer is rated at 180 gallons so I'm guessing this is the manufactures ratio. Realisticly that is not very much water in an hour and I doubt every one is calculating this out before buying skimmers and pumps. This make me rethink my plan and should probably only run about 200GPH through my sump. Not to ramble on about my system but just to give a little useful info.

I would try to use the T-4 for your sump pump if you think it can handle the head pressure. Even if it only gives you 3-4 hundred GPH it will be plenty and you will gain the 700GPH loss back with the barracuda on your closed loop

[edit] Correction. The reefs.org pump selection guide shows the T-4 as having 1100GPH at 10 of head so you would actually be gaining flow in your display by switching the two pumps with each other.

 

[jsteel]

i had the same problem in my sump and a friend who has an ecosystem sump told me to use bioballs in the baffle area to break up and catch bubbles in the current. i have three baffles before the skimmer section and i stuffed bioballs in all three sections(probably overkill) and i couldn't believe how well it worked. also, since the bioballs are underneath the waterlevel there is no risk of the trickle filter syndrome. it also seems to be a good housing for cryptic life forms as i have seen many sponges, etc.
on the balls. it might be a simple solution to your problem.

 

[Sponge_Bob]

The only solution I can think of, since you don't want to restrict the flow out of your pump, would be to raise the water level in the sum. That means, change all the baffles and make them higher. Furthermore, you will have to make sure that your sump will still be able to handle the overflow coming fom the tank in case of a power outage. Another way to possibly... and I mean possibly solve your problem would be to put a sponge on the intake of your pump if none is present. If one is present, try to make yourself a bigger one and see how this helps.

You might just have to implement the 2 above strategies together in order to get satisfactory results. Make no mistake, I can not guarantee you that it will work. I still think that your pump is an overkill and way too powerfull for the job. But since your are stuck with it....

 

[Anonymous]

O.K. Did some looking. The T-4 is rated at 1250GPH at 3' of head. The Barracuda should be giving you about 2700GPH at 10 of head. I am in the process of designing my pump system for my 120. So im researching all of this info. By the way. How big is your display tank?
The general rule of thumb is to only run through your sump what your skimmer can run through in any given hour. Scientificly, the skimmer will function most efficiently if it circulates the total volume of tank water 10 times in a 12 hour period. So for my 120. Only 120 gallons an hour through the skimmer. My skimmer has a sedra 5000 rated at 500GPH. With a needle wheel and a venturi my guess is that is will only pull 30% of that water capacity at 150GPH. My skimmer is rated at 180 gallons so I'm guessing this is the manufactures ratio. Realisticly that is not very much water in an hour and I doubt every one is calculating this out before buying skimmers and pumps. This make me rethink my plan and should probably only run about 200GPH through my sump. Not to ramble on about my system but just to give a little useful info.

I would try to use the T-4 for your sump pump if you think it can handle the head pressure. Even if it only gives you 3-4 hundred GPH it will be plenty and you will gain the 700GPH loss back with the barracuda on your closed loop

[edit] Correction. The reefs.org pump selection guide shows the T-4 as having 1100GPH at 10 of head so you would actually be gaining flow in your display by switching the two pumps with each other.

I actually like this suggestion the best....