Micro bubbles in display, suggestions?

[reefknight]

I have a good number of micro bubbles entering my display and it is quite annoying. I was given one suggestion on how to fix it, but wanted to see what others had to say on the subject as well.

Sump is a 50gal breeder divided into two sections. Skimmer section, which has (2) 1" drains running down with 90 degree elbow outputs and an Alpha 200 skimmer. Water then enters a series of (3) baffles. The baffles are spaced 1" apart and the one that flows under has a 1" clearance. Baffles in which water flows over are 8", under is 10". (That includes the clearance from the bottom of the sump.) Water flows over, under, over to the larger remaining area of the sump containing the return pump. (ATB Flowstar 1500). The return line is Tee'd to feed a media reactor and I have dual return lines. Each has a ball valve which is throttled back a tiny bit. Sump originally had a refugium side as well, with the return being located in the center. After about a year I decided I didn't care for it and removed the glass baffle to make one large chamber at the end.

When speaking with one individual it was explained that my error and cause of micro bubbles was due to the last baffle. He stated that it should have been an under, not an over design. Though I have seen plenty of systems designed exactly like mine. I have considered draining the sump, pulling it and installing the under baffle but would like to hear other ideas first.

My drains are homemade durso designs, dual 1.25" that reduce to 1" after the bulkhead. I do not run filter socks for the most part. If I do a lot of maintenance I may place a mesh bag on the return for 24hrs to catch any large particles that I have disturbed. I have not cleaned out my sump in a while and there are particles in it. Just bought a small shop vac last night and that is on the immediate agenda. SKimmer does not produce many micro bubbles or that I can detect. Media reactor contains GFO and returns to the first chamber.

That pretty much sums up the system in general and should answer any questions, so please let the suggestions begin!

Thanks folks!!

 

[Reefing Madness]

Gotta watch the intake of the return pump. Do you see any bubbles in that area? You can always install a sponge in that last chamber area to absorb the bubbles getting in there.
Or your picking up the bubbles from a turbulent bend in the return somehow.

 

[reefknight]

Haven't seen any bubbles in the chamber. I am considering grabbing a couple of foam blocks and cutting to fit the final baffle. If not that then it could be a bend in the piping. I have a few 90 degree elbows in place as space was cramped on the install.

Have to try the foam first. If need be I may have to re plumb the pump.

 

[Reefing Madness]

Right on. Im leaning towards the plumbing. But, gotta trouble shoot it first.

 

[Coral Dreams]

Do you happen to have a picture of your setup.

 

[feh]

Pics would help in troubleshooting. If the bubbles are caused by the drain I'd recommend first redoing them so they drop at no more than a 45 angle and box the drains in with glass / acrylic depending on what the sump is built from. The box should be slightly higher than the water line, but you don't want a waterfall. When you silicone/glue it in glass don't silicone/glue around the bottom of the box. Also a reverse durso may help. If its the return check for any place air may be getting in.

 

[AZDesertRat]

Pics?

I have an over-under-over baffle arrangement on my 30G sump and have no bubble problems at all.

How is the return pump plumbed and placed in the sump? How deep is it submerged? What does the plumbing arrangement look like as far as size, fittings, valves, length and how or where does it return into the display?

 

[mainereefer]

with my sump I have a cheato wall last to catch the bubbles and anything that makes it past the skimmer and refugem

just take a piece of egg crate and push cheato threw the holes in spots add a light it will fill in and you will have one of the best filters you can get

 

[Reefing Madness]

I've got a sump with no baffles, just egg crate to creat a holding area for the cheato and caulerpa, and a 1200gph powerhead to circulate the water. I don't have any bubbles.

 

[cPr]

Throw up some pics so we can troubleshoot for you, I would say that having the over not under for your last baffle ISNT the reason for the micro bubbles but thats without seeing it.

I would add a filter sock and maybe a couple sponges, if you decide to add sponges make sure you remember to take them out and clean them regularly as not to have a build up of detritus, try having your return pump dialed down a little bit see if that helps also.

Pics would really help us though

 

[mcarroll]

So are the bubbles coming from the drain, or the baffles, or you can't really tell?

Too much flow through a sump is not uncommon as a source of bubbles...sometimes they can still be dealt with though.

If possible, try slowing down the overall throughput and see if that alleviates your microbubble issue. Remember 2x-4x tank turnover is all the flow you really need through you sump and filters.

-Matt

 

[reefknight]

Thank you for the suggestions guys. Between work and a couple other issues, I haven't been able to update the thread. Okay, to begin I bought a few of the Hagen foam filters for their power filters and lined the last baffle. No joy there, bubbles are still returning to the tank. At the same time I was cleaning the pump on my skimmer so it was down, so it's not the culprit either. It's the plumbing for sure now. I'm trying to get some shots uploaded of the sump area, but am running into problems. My photo upload account hasn't been used in so long they discontinued it. Getting another set up and will have some photos up.

I do know that the water comes down and into the sump pretty quickly and there is some turbluence in the first chamber. I was examining this closely while installing the skimmer pump. I did notice the bubbles are making it through the baffle system to the final area. Drains are homemade 1.25" durso's that reduce at the bulkheads to 1". From the bulkheads the pipe goes immediatley into true union ball valves, drops about 9" then turns left for a horizontal run of about 15" to the sump. The fittings are partially submerged at the water line of the first chamber of the sump.

The return was a little tricky due to some of the features that I was attempting to incorporate. PVC comes straight up out of the union fitting on the FLowStar about 14" turns 90 degrees and runs for about 4". It then makes a split. The right side goes straight to the true union ball valve for the return on the right side. The left goes to a tee where it splits again. Water runs to the left return as well as down a pipe about 15" where it feeds a 1/2" ball valve for a GFO reactor and that pipe terminates into a 3/4" ball valve that is always shut. That ball valve is only used for water changes.

@ feh - Being in ATL, I'm sure you are familiar with Jorge( Pure Reef). He and I went over the plans for the plumbing like three times, lol. I told him I wanted to be sure of two things; quiet as possible and no bubbles. Well its halfway there!

 

[mcarroll]

Use those valves to cut down your flow to 4x display or so (even down to 2x) and see if the problem goes away.

-Matt


Sent Via the R2R Forum APP

 

[reefknight]

I found some photos of when I was first setting the system up. It's easier to see what was going on then, lol. I have changed a couple of things since though, the refugium side of the sump has been removed and the drain going to it has been as well. I just shut off the ball valve and removed the union fitting. Skimmer changed as well to a Vertex Alpha 200.

First photo shows the return scheme along with the ball valves for the returns / drains.

http://imageshack.us/a/img687/761/img0295pa.jpg


Second shows a side view of where the drains empty into the sump, skimmer section and also the ball valve that is used during water changes. The straight downward pipes have been shortened and 90 degree elbows have been added to the drains. Those were on there to eyeball it until water was added and a water level was determined.

http://imageshack.us/a/img94/9939/img0294lp.jpg


While throttling back drain / retrun valves I did find something amiss. I have a slow stead drip from the right side return plumbing, beneath the ball valve at a 90 degree elbow. If I throttle that ball valve back it drips, if its wide open it doesn't. I guess I know what I will be doing on my next day off. :sad:

 

[casey187]

sounds pretty simple but have you checked your return pump? sometimes small debris in the pump can cause micro bubbles. I would check that before the plumbing.

 

[AZDesertRat]

That drip may be acting as a venturi and sucking air in when you don't have the additional head on it. You may also be getting a venturi effect where the return line tees off to feed the reactors. It doesn't take much. When you throttle the flow do the bubbles disappear or at least reduce? If so velocity through the pipe and possible venturi effects or eddy currents from elbows and fitting restrictions may be the culprit. I may be old school but I prefer oversized reinforced vinyl tubing with gradual sweeps or bends and minimize my PVC use to near bulkheads and valves so I get a nice laminar flow. I have found a mixture of tubing and PVC works well for me and is quieter than rigid PVC too.

 

[reefknight]

sounds pretty simple but have you checked your return pump? sometimes small debris in the pump can cause micro bubbles. I would check that before the plumbing.

I cleaned the pump about 2 weeks ago, but it's not to say that it hasn't picked up something in the meantime. It'll come off on Monday and be checked, as that's my next day off.

That drip may be acting as a venturi and sucking air in when you don't have the additional head on it. You may also be getting a venturi effect where the return line tees off to feed the reactors. It doesn't take much. When you throttle the flow do the bubbles disappear or at least reduce? If so velocity through the pipe and possible venturi effects or eddy currents from elbows and fitting restrictions may be the culprit. I may be old school but I prefer oversized reinforced vinyl tubing with gradual sweeps or bends and minimize my PVC use to near bulkheads and valves so I get a nice laminar flow. I have found a mixture of tubing and PVC works well for me and is quieter than rigid PVC too.

When playing around with it I really couldn't tell that anything was reducing the amount of bubbles. You're correct though, as I know an unsealed pipe can cause bubbles. Monday it's back to the drawing board, so we'll see what happens. I'll have to re plumb the return now as there is no choice in the matter. A small leak today equals a flood tomorrow. Since I have done away with the refugium I may be able to do away with some of the weird bends and 90 degree elbows. I should also not have to have that initial pipe come straight up like that this time.

You know it's funny, I've done installs on prior tanks with either reinforced vinyl or pvc flex and haven't had the bubbles, but noise. I usually get the return wanting to knock against something. I do agree though that I despised the amount of elbows that I had to use at the time of the install of the tank. I figured someday I would have a custom sump made and I would re plumb then. Guess the plumbing cam before the sump.

 

[reefknight]

I was able to re plumb the return pump yesterday. Much cleaner install now, but still micro bubbles. Began playing with throttling back the drains and the return flow. I think I may have found the answer. I had a lot of turbulence in the skimmer chamber from the drains. Plenty of bubbles and air getting into the chamber, since reducing flow it has has reduced them dramatically. I'm going to give it a couple of days and see how it settles in.

 

[AZDesertRat]

The drains or overflows should never be restricted in any way unless you have the "herbie" design which has a built in back up. The return pump is what regulates the overflow rate so a simple ball valve on the discharge controls the elevation in the display and the overflow rate or velocity through the system. If you have turbulence in the drains then maybe the piping and flow are not laminar and the water/air mixture may need to be adjusted. What do the standpipes and caps look like?

 

[mcarroll]

The drains or overflows should never be restricted in any way unless you have the "herbie" design which has a built in back up. The return pump is what regulates the overflow rate so a simple ball valve on the discharge controls the elevation in the display and the overflow rate or velocity through the system. If you have turbulence in the drains then maybe the piping and flow are not laminar and the water/air mixture may need to be adjusted. What do the standpipes and caps look like?

+1 +1 +1

The easy solution is just to throttle down the pump with a ball valve on the OUTPUT ONLY in small increments until the bubbles are down to a satisfactory level.

If you're up for more plumbing changes (or my advice results in less the 3x tank turnover in flowrate) definitely follow the above advice from AZ and see if the drain itself can be improved further.

-Matt