TUNZE ALGAE REACTOR -- FRUSTRATING PROBLEM

[Dr. Jim]

I recently set up a new Tunze Algae reactor with a baseball-size ball of chaeto and found that when air bubbles get into it, all the Chaeto floats to the top so it doesn't rotate as it should, and this causes a vertical line of the algae to burn (from being right next to the vertical light) which is killing the chaeto.
It seems impossible to keep air out of it because whenever you shut it off to open it (e.g. to shake off the bubbles), more air is introduced. I suspect that if the chaeto grew to the point where it filled the chamber it would then rotate, but it doesn't seem likely it will survive that long seeing how it burns when it doesn't rotate.

Any suggestions are appreciated. Thank you.

 

[rvitko]

Things to check and I attach a video on proper installation-



1) Is the outlet possibly over the pump or is something draining over the pump and knocking in air bubbles that the pump is taking in?

2)Is the outlet hose or inlet hose kinked or is the pump possibly sucking down to the glass, in these cases cavitation can create bubbles.

3) Is the tank very nutrient rich, or possibly with high CO2 where photosynthesis is generating bubbles? In this case shorter or interrupted light duration would likely solve it.

4) Is the flow rate really high? The pump should be at a very low speed for a sump install, rotation is far less important than not blowing the chaeto to the top. If the chaeto doesn't turn at all this is no consequence for a small clump, if it turns 1-2 rotations a day it is fine for a larger clump, you do not need to have it rotating at a visible pace, it will spin with a much lower flow rate but may only be visible with a time lapse camera. Generally, small clumps do not rotate well, neither does a full reactor.

 

[Dr. Jim]

Things to check and I attach a video on proper installation-



1) Is the outlet possibly over the pump or is something draining over the pump and knocking in air bubbles that the pump is taking in?

2)Is the outlet hose or inlet hose kinked or is the pump possibly sucking down to the glass, in these cases cavitation can create bubbles.

3) Is the tank very nutrient rich, or possibly with high CO2 where photosynthesis is generating bubbles? In this case shorter or interrupted light duration would likely solve it.

4) Is the flow rate really high? The pump should be at a very low speed for a sump install, rotation is far less important than not blowing the chaeto to the top. If the chaeto doesn't turn at all this is no consequence for a small clump, if it turns 1-2 rotations a day it is fine for a larger clump, you do not need to have it rotating at a visible pace, it will spin with a much lower flow rate but may only be visible with a time lapse camera. Generally, small clumps do not rotate well, neither does a full reactor.

The problem is not air getting sucked into the tube but rather whenever the unit starts up (e.g. first time use or any time you stop pump and open chamber) air gets into the intake tube and that creates lots of bubbles that get caught in the chaeto causing it to float. Even in the video you posted, you can see those bubbles going into the chamber. (There was no chaeto in the video, but if there was, it is easy to understand how tiny bubbles would get trapped in the chaeto).
I really don't see any way to get this to work with a baseball size chunk of chaeto which would be a practical size to get started with.

 

[rvitko]

I use a 3182, in sump at least, the reactor is never empty, all I do is push the chaeto down into the water. Bubbles cause it to lift and tumble but they settle and the unit works normally, the chaeto eventually settles down if the flow rate is not extreme and no more bubbles are coming in. By the end of the video, the column is almost completely free of bubbles, they should purge out and no more bubbles should enter once the hoses and pump are purged. You also can see the flow was set very low. Air bubbles should not be causing this much trouble and I don't believe they would kill or burn the chaeto, I generally see chaeto sold prebagged just wet, not in water, it doesn't seem to harm it. These reactors are not new, they have been available for a few years and this would be the first case I know of that was not a cause I outlined that was simple to remedy. Is your possibly instaleld someway it is emptying completely like above the sump?

 

[Dr. Jim]

I use a 3182, in sump at least, the reactor is never empty, all I do is push the chaeto down into the water. Bubbles cause it to lift and tumble but they settle and the unit works normally, the chaeto eventually settles down if the flow rate is not extreme and no more bubbles are coming in. By the end of the video, the column is almost completely free of bubbles, they should purge out and no more bubbles should enter once the hoses and pump are purged. You also can see the flow was set very low. Air bubbles should not be causing this much trouble and I don't believe they would kill or burn the chaeto, I generally see chaeto sold prebagged just wet, not in water, it doesn't seem to harm it. These reactors are not new, they have been available for a few years and this would be the first case I know of that was not a cause I outlined that was simple to remedy. Is your possibly instaleld someway it is emptying completely like above the sump?

It is on same level as sump.
I had it on highest speed because that was recommended in the "Directions." I will try slow speed and double check for bubbles leaking in from sump.
Thanks for helping.

 

[rvitko]

This is where I would focus. In a typical sump installation, once you start the pump the first time, the air is purged from the pump and the hose and the reactor stays full to sump depth. No air can get in this way after the first run unless you remove the pump from water, water is captive in the line and pump. For service all you should have to do is open the lid the pump if it stays in water no new air can be introduced, somehow the hose is draining all the way and letting in air or air is getting drawn in by the pump.