thomas01 wrote:

---

I too installed a cassette ventilation system about a year ago and agree that there is no smell inside the van at all from the cassette.

Outside the van is another story. Although the system comes with an external filter it does Jack you know what. Before someone says that the filter needs replacing, it was like that from day one.

The SOG and similar systems are great for free camping where your neighbours are parked outside of the "smell zone". No chemicals are needed and the cassette contents can be emptied into any septic without fear of contaminating the system. When in a caravan park where you neighbours are within a metre or two of your van the story is a bit different. This is particularly evident with angled drive through sites when the toilet cassette of your van is adjacent to the outdoor seating area, ie: the neighbours awning. In cases like that I have disconnected the cassette ventilation fan so the neighbours don"t get the "aromas' every time you use your loo.

I ask others with these types of systems to advise if they have experienced the same "aromas" outside their vans when the toilet is being used, or is it just that my crap stinks more than other peoples.

I would like to know.

Regards Robert

---

Robert,

Yep, I am aware of the smell of roses outside especially when just turned on for use.

But as a general rule its likely that except in periods of heavy use there's a slow leak of

 roses that is usually not noticeable.

You can also get a whiff when others use the potty and your windows are open and a waft

can come in.

A failsafe assistance is to have a pressure sprayer with a mix of water and sodium PERcarbonate

under good pressure and use this as a pressure spray when some roses are clinging to the exit

of the bowl. Intelligently used this will mostly alleviate the necessity to flush with water and

thereby save your water supplies and not fill the holding tank so rapidly.

Sodium PERcarbonate is available online or use 3X the quantity of NappyySan VANISH.

I have a 1 liter pump sprayer and adjust the nozzle to a fairly narrow spray.

will keep the bowl nice and white also. $7 at Bunnings.

I use 1 teaspoon to a liter of water.  3 teaspoons of NappySan Vanish.

And last recommendation - change your diet!

B

A good question Thomas. I commend you on not wanting to use chemicals except that some chemicals are better than others.

Rather than buy the stuff available at camping and caravan places I use sodium percarbonate. This is the active ingredient in Napisan and similar. In the supernarket, usually the no name brands have a higher concentration of the active ingredient and cost much less.

This one is 32% sodium percarbonate (see label on the back).

Generic laundry soaker

You can also buy 100% sodiium percarbonate from most brewers' supplies. Sodium percarbonate is friendly to the environment as opposed to the typical toilet chemicals which are not.

Following some comments online I may have been using more than others, but I currently put in about a desertspoon on the first use, and a bit less each time it is used after that. For a bit of freshness, a couple of drops of eucalyptus oil on the bowl after use. There is no odour, and any solids quickly disintegrate. When emptying after say 3 days there is hardly any aroma. Incredible stuff and most long term travellers use it.

Sodium percarbonate works quickly and breaks down quickly.
For the best results, we add 1 teaspoon full, dry, for each #2. More is not better.

This is an explanation from Frans Harmer, an Industrial Chemist who is also a full time motorhomer.

Franz Harmer, retired industrial chemist.

"Sodium percarbonate is also known as Sodium Carbonate Peroxide (PCS) which is probably a better general description and its chemical name is Sodium Carbonate Peroxyhydrate.
Its chemical formula is (Na2CO3)2(H2O2)3and as you can see there is a fair bit of oxygen there. Pure sodium percarbonate contains about 13% oxygen.
It is the product used in all those adverts you see for various products supposedly oxygenated and have that miraculous oxi or oxy action which includes those washing powders we put into our washing machines and where applicable into the septic systems.

The misunderstanding about PCS is the fact it is promoted as a bleach even if it is an oxygenating bleach.

We have all been brought up to consider bleach as evil in some regards. Unfortunately, this bad bleach is chlorine based like the stuff we throw in swimming pools to kill the bad bugs and if introduced into septics, it kills the good bugs. Formaldehyde which is contained in some of the chemicals for toilet casettes is also in this category.

So the problem here is the general reaction by those not knowledgeable in the difference, see the products containing PCS as a bleach meaning it is bad which is the opposite to the facts.

Just to clarify to some who may have seen other names for oxygenating bleaches, there are 3 types of oxygen bleaches generally available - hydrogen peroxide, sodium percarbonate (which we shall continue to abbreviate as PCS) and sodium perborate.

If we understand how PCS works, we can see why they are not at all harmful to septics.

Those familiar with common chemical compounds will see that PCS essentially contains sodium carbonate and hydrogen peroxide stuck together. It is made by treating natural soda ash with hydrogen peroxide and the oxygen is absorbed while remaining a free flowing solid.
Upon dissolving in water, it breaks back down into natural soda ash after the oxygen is released. The oxygen is used up in your toilet cassette breaking down the stuff that is in there, and you are then left with the soda ash which can do no harm to any septic.

Now lets turn the argument around from why is PCS not harmful to septics to what can there be to harm a septic system.

When PCS is broken down we have sodium carbonate which has a higher than neutral pH. Septic systems will fail at lower pH and require higher levels to stay efficient. The septics that smell usually have an acidity problem which is killing off the bugs. A means of correcting this is to raise the pH by the addition of lime. Sodium carbonate has a similar effect, however the comparatively minute amount we are putting into a septic will really have no effect, but if it does it will be positive.

In fact it is recommended that bicarbonate of soda (sodium bicarbonate) is used as a cleaner for septics. Sodium carbonate (the left-over from PCS) has the same chemical effects as Bicarb so that can not harm the septic.

The usefulness of PCS in our use is the generation of oxygen. The basic septics are anaerobic and this could be one of the reasons for the misconceptions about using PCS products with septics if there is an assumption that the oxygen will ruin a septic.

This argument also doesnt stand up to scrutiny. Firstly, we are using a teaspoonful per day which lets face it is bugger all. At that rate, all the oxygen will be used up trying to cope with the stuff in the toilet, so by the time we dispose of it there will be no free oxygen and even if there was, there would be nowhere near enough to adversely affect a septic.

Secondly, the same would apply to all those Oxy washing powders and cleaners (all PCS) which are all OK for septics and if anything, would deliver more free oxygen than our cassette or black water tank.

Thirdly, although septics are an anaerobic system, they are unaffected by the introduction of a little oxygen. Aerobic systems require the introduction of oxygen. Anaerobic systems do not require oxygen and work best without it. This does not mean that a little oxygen will kill it.

So if anybody with a septic believes that the PCS products are bad, they will need to stop using most of the modern day "safe for septics" PCS bleaches, cleaners, dishwasher powders, washing powders etc.

By all means use the generic nappy treatment products if they say they are septic safe on the labels.

Where can there be a problem with these products? Only where there are other compounds in there which are not septic friendly so it is important to read the label to make sure the one you use is OK for septics.

Because the oxygen is released as soon as it is dissolved in water, I would suggest a teaspoon of the powder per day directly into the toilet. It will release the oxygen a little more slowly.
Keep in mind it will be absolutely useless if you only pee in the toilet - you will need to use something else.

By the way, do you know why they are called septics? Simply, because they are septic. They are full of Eschericia coli (e-coli lives within our large intestines in a symbiotic relationship with us as it is a source of vitamin K). So, anaerobic systems are "septic" (meaning contaminated with microbes) and must be isolated from surface water and well aquifers and is a reason you can not locate your septic trench near a stream or underground water supply."

Cheers,

Peter