Best way to add a second vent?

[Chris & Lenore]

Wow - I was away for a few days - lots of comments...

But I still have the question of what should I do. I have had no problems with the current setup - which has a single 1/2 ID vent. But I have have read numerous times that a larger vent or two vents is "best".

Should I add a second (using the fitting Peggy suggested) or increase the size of the existing (which would also dictate one of those fittings and a plug I the existing hole)?
I don't think I need to use bubblers etc. as I tend to pump out every week or two. Actually, I have never seen or heard of anyone doing that (at least at our club).

Chris

 

[Ralph Johnstone]

Goes to Show You .....

Wow - I was away for a few days - lots of comments...

But I still have the question of what should I do.

.................. shouldn't go away for a few days. Don't know what might just happen around here.

What you should do depends on what you want to achieve. What you've got works without danger of rupturuing the tank (+ or - pressure). Unfortunately it stinks. Correct the problem by ventilating the tank and going aerobic.

I suggest taking it in steps. Simplest to most $complex$.

RichH 's suggestion of how to make an attachment to the inlet hose for the second dedicated vent line and thru hull is simple and clean. No need to open the tank. Keep the second vent line and thru hull about 1" or greater if possible. Avoid low spots.

Still not happy, increase the size of the first vent line and increase its thru hull size.

Still not happy, increase the size of the tank fittings. Now you're really getting dirty.

Still not happy, as a last resort, install an aeration pump and risk draining your batteries to zero if shore power fails. Or install a DC voltage limiter which opens when the V gets too low so the battery doesn't drain in the event of lost shore power. Or spend a small fortune on solar panels for your holding tank.

If it were me (and I'm OCD), I'd install the second separate dedicated vent line as per RichH's suggestion and then forget it. Something about the law of diminishing returns.