I got your PM and will answer in more detail than is practical in a discussion forum:
1. Holding Tank Vent Placement: She says ideally, the run should be 3', but no more than 5'. She also says that the rise of the vent line should be no > 45 degrees. I can't satisfy either of these requirements easily. Rather, I can do about a 6' run, with most of it being horizontal, turning up slightly at the end (near the bow of the boat), or a 4' run at an angle much higher than 45 degrees. Thus, which is the lesser-of-two evils?
Originally Posted by Captain Safety
I just bought Peggie's new book, "The New Get Rid of Boat Odors," and found a lot of good, pragmatic, information. That said, I have four questions on which I would appreciate guidance:
The mostly horizontal 6' run is the better choice.
2. She also mentions that on a sailboat, the topsides near the bow is a good location. It seems that in heavy seas, this would bring in a lot of sea water, no?
Just splashing won't put enough water down the vent to worry about. You can prove that to yourself by aiming a garden hose at the opening of a 2 liter soda bottle from several feet away .However, if you're a blue water cruiser who's likely to spend a couple of days in conditions that keep your decks awash, I recommend installing a shutoff valve--even a seacock--in the vent line that you can close when heading into heavy weather
. You'll be flushing
the toilet directly overboard
at sea anyway, so it won't matter if the tank can't vent. Just remember to open the valve again before starting to flush into the tank again.
3. She suggests a 1" vent hose, however my new tank comes with a 5/8" fitting. If I put a 5/8" to 1" adapter onto the fitting, will that improve airflow or would I need to try to get a 1" replacement fitting (if that's possible)?
If you haven't bought the tank yet, specify a 1" vent fitting when you order it. If you have bought it, you'll need to install a new vent fitting in the tank...which is actually very easy to do and inexpensive, thanks to a li'l gizmo called the Uniseal UNISEAL
A Uniseal and a short piece of PVC pipe for a hose fitting is all you need.
4. Bilge Cleaning: Peggie mentions the downsides of many bilge cleaners, but she doesn't suggest what is the best thing to use (effectiveness, environment, etc).
I don't discuss the downsides of any bilge CLEANERS, only what passes for bilge CLEANING among too many boat owners. Any good detergent detergent cleaning product will work just fine...but product claims to the contrary, you can't just pour something into a bilge, let it slosh around for while, then turn on the bilge pump(s) and call it done, and expect to have a clean bilge...any more than you can just pour some Dawn into a sinkful of greasy dirty dishwater, slosh it around, then just pull the plug
and expect to have a clean sink.
Btw...my new book is available in both hard copy and Kindle from Amazon.