inline oxygenation sight tube question

[0verdrive]

I'm planning on building an inline oxygenation system, using a diffusion stone and an O2 tank with a flow meter. From what I've read online, I may not need a sight tube, since the flow meter should be sufficient for ensuring that I'm not putting too much O2 in the wort. But I have the parts already, so I thought I'd build it in.

But I still have a couple questions that I haven't been able to find online, and I'm hoping someone else with a sight tube can give me some advice.

1) Does it matter whether the oxygenation system is mounted horizontally or vertically? It would work better for my system to mount it vertically, but I worry that the O2 bubbles will flow upward too quickly to see them, which would defeat the purpose of the sight tube. I could resolve this by making the sight tube longer, but I don't want it unnecessarily long.

Which leads me to my second question:

2) How long should the sight tube be? Does whether its mounted horizontally or vertically make any difference in how long it needs to be? How long is long enough to see bubbles?

Thanks for your suggestions!
~Dean

 

[Huaco]

I just built one from SS Fittings and a clear PVC 3/4x3" nipple. I am thinking about replacing the clear nipple with a SS nipple because of the very reason you state. If I know I am putting O2 into solution, why do I "NEED" to see it? plus, with mine being constructed of threaded fittings, I want to be able to boil the entire assembly because it is on the cold-side.