micro bubbles, cavitation help?!?

[gannmann9876]

this is my first sump set up and it is driving me crazy. i have a serious micro bubble problem. i have a iwaki 40 return pump 1" in and 1" out it then has a "t" fitting that splits into 2 3/4" lines that go into the overflow which is a 1/2" line going to the return lines. the tank was setup like this when i bought it. i tried puttin a"y" fitting in place of the "t" but the bubbles are worse. they come in spurts whereas with the "t" they are constant. what do i do i am frustrated and clueless!!

 

[pelagic7]

I am not expert of plumbing. Here's a cheap way to reduce the bubble. I hope it helps.

pic1: when it's working
pic2: not enough water, needs to adjust the water level
pic3: the pic of what it looks like.

 

[gannmann9876]

i think maybe change the loc line and the hose running to them to 3/4" i just didnt know if there is a rule of thumb when it comes to hose size from return pump and what is the smallest size you can split into for cavitation not to occur. maybe i need to run two return pumps

 

[commonstranger]

Hmmmm can you post some actual pictures of the sump set up and the plumbing pieces your talking about. This is plumbing problem it cant be too hard to fix but without looking at it Im clueless.

 

[Pickupman66]

is it straight in from the sump? if you have a turn just below, you can create turbulence that will cause microbubbles.

 

[Mikeyjer]

Micro-bubbles going into the sump? If that's the case, why don't you use filter socks or rock rubles on the bottom to break it up?

 

[gannmann9876]

they are not going into the sump they are going into the tank out of the return pipes. i was wondering if you have 1" line out of the sump into the return pump how to you plumb it to 2 return lines. i have it split into two 3/4" lines that go into bulkheads that reduce to 1/2" line inside the overflow and then go to the returns. maybe change the 1/2" line inside the overflow that goes to the returns? i dont know how much you can reduce the line without making it cavitate. i dont know how to load pics on here but i think the problem is in the return lines i was just wondering how you guys plumbed your tanks if you have 1" overflow and 2 3/4" return lines. do any of you run two smaller return pumps instead of one larger one?

 

[gannmann9876]

its not hard plumed it is just hose but yes it is strait from the sump

 

[commonstranger]

If I get time this weekend I might be able to ride up and give you a hand if you like. Not saying I can fix it for sure but I will try and help if you like.

 

[Pickupman66]

Hmmm... so you are using hose and not hard pipe? im assuming there are hard fittings at your joints ("Y" and INlet and outlets? I would upsize those to 3/4 or 1" after your "Y". what happens with that type of fitting is that it is designed to fit Inside the tubing making its Inside Diameter smaller than that of the hose it is connected to.

Hope this makes sense. If you can go with hard PVC, it may help the overall functionality of the system. I prefer hard pipe and only use flex tubing to buffer vibration.
My tank had a "Closed Loop" system on it. I had a bad micro bubble issue. i fixed it by 1" in and 1" out even after the "T" to split the sides. I also put oversized unions by the pump as they 1" ones had a much smaller diameter inside than the rest of the pipe.

 

[gannmann9876]

Yeah that makes sense.I was thinking about changing to 3/4on the return lines. Rhett any help would be appreciated when I come to get the fish I will look at your sump

 

[andywe]

SOrry I am out of town or would glady have hopped over from Mt. Juliet. If the bubbles come in spurts it really makes me think you might check that your punp isn't over running your sump. If the pump pulls the water level too low air will be intorduced into the return line. If you have a ball valve, you might try reducing the flow output to see if it helps. Jsut another thought for you

 

[fowlr2reef?]

@ one time i had a micro bubble problem in the past due to my protien skimmer. the return dropped straight down into a sponge. removed sponge completely and spun the 90 degree elbow so that it was at a 45 degree angle, then cut a piece of pvc at an angle so that the water just trickeled down at a slow incline. this solved the micro bubble problem for me. the micro bubbles from the skimmer were being drawn straight into my return pump by the time it reached the tank it looked like a snow storm in there. this may not be the case with you. this is something that is overlooked at times. i fixed it many moons ago before i even knew r.c. or mtrc existed. good luck.

 

[ai-reefer]

when the water first hits the sump, its better for the water to enter into a small separate chamber so to speak. This gives the bubbles time to "settle". If you dont have a chamber, you can use a 3" PVC and drill a hole at the bottom of it. The water would go into this pvc pipe and 80% of the bubbles end up bursting in the pipe itself before the water comes out to the rest of the sump.

You could try different configurations to see what works best and it would be fairly cheap to experiment.

Im about to do this because i have the exact same problem as you. I'll definetly post some pictures.

 

[gannmann9876]

it is very annoying ai reefer i feel your pain. i will try the suggestions you guys have given me. the sump level stays the same and i have unplugged the skimmer to see if that was the problem as well. where i have the "t" fitting i replaced it with a "y" fitting and the bubbles were worse so maybe cavitation? with the "y" they come in spurts but a lot worse from what i have read online it sounds like cavitation. i would like to know how you guys have your sumps plummed.