Mark L

I can indeed say that there will be a review in WW soon. I engaged in the trial of the Axiom props on the River Nene and will be following the hire boat trial as well. Will let people know the issue it will be published in, when I know! Regards, Mark Langley Technical Writer Waterways World

Following on from a recent discussion about tests on toilet fluid, I use Blue in the bottom tank (the marinas own, cheap version!) and disinfectant (cheap, "ocean fresh") in the top tank (300ml in 15 litres water). Quite cheap, and works very well! Seems to be the best combination I have tested so far! However, pink in the top tank also works well. I also give the top and bottom tank a damn good clean (with ecover washing up liquid!) every few weeks! I tend to store the spare tank full for up to a week, and there is very little smell when emptied! From what I read on here, everyone seems to have their own ways!

If you go down that route, would you want to take all the boaters income (commercial, non-commercial, shared ownership, etc) and divided it equally? Then there would be a massive increase for most private boaters...! (editied for crap spelling!)

Just to note, most hire boat companies average out between 18 and 25 weeks hire per year. They already pay a very large premium over other boaters fees- as you would expect. However, unlike CCer's, they don't use the system 52 weeks of the year.... so in that respect, I can see that people who don't have a home mooring (and hence saving costs in that area) might be considered for paying a premium, as they do use the services more. I am not quite so sure about the broad beam costings though- as the cruising range is already restricted. Mark

WEll, I have anecdotal eveidence from a number of boaters (with large holding tanks, admitedly) that say that Biomagic doesn't work for them! However, often it is down to how boaters use it- and I will be trying it again, after peoples suggestions. I am not suggesting that Formaldehyde / methanal /methanol bases treatments are best- far from it. However, they can render the waste much safer to handle than either raw sewage. Sludging is a problem with all holding tanks, regardless of treatment. I removed a tank from a boat that never had any treatment used, and it still had a good 2 inches of solid sludge at the bottom. The sludge come from fibre, and the remnants of dead microbes- and yes, formaldehyde does encourage this. However, unless you have designed the tank well (sloping bottom to the pick up, several well-spaced 360/180 degree spray nozzles) and clean the tank throughly at pump out, there will always be sludging. The more often you pump out, the less "crap" in the bottom, so to speak! Hire boats fare a lot better in this respect, from my experience. Microbial treatment systems work well, if there is a good throughput of air (see earlier). IN the USA and other countries, onboard waste treatment plants effectively decompose the waste so it is in a fit state to be discharged overboard- using settlement, aeration and bacteria. However, they are large- and currrently wouldn't be allowed to discharge the treated effluent into our watercourses. However, would then be perfect to empty at a pump out! Incidently, my most successful treatment, using my porta potti, seems to be 50ml Elsan Double Blue in the bottom tank (low dose) with a relatively cheap disinfectant (150ml) in the top tank- diluted to 15 litres (a 1:100 solution). Seems more effective than the "pink" rinse solution. I suppose I should go to do some work now! Off to Wrenbury!

But bio-magic still needs a good supply of oxygen... it contains aerobic (or encourages them) bacteria..... without enough oxygen, they do very little... and the stuff then replies on surfactants and enzymes instead. And enzymes are rather specific. It does smell nice though! Oh, and though its an "oxygen rich" liquid... unless its H2O2 (hydrogen peroxide- which I doubt) it can't supply much oxygen to the tank. I agree it works well in cassette toilets, but not over long periods. And in our tests, it didn't break waste down particularly effectively. And the bacteria counts showed potential pathogens as well....

It might be possible.... mine are on the roof (ex hire!), but now discarded for a Porta Potti (and I never ever want to go through removing a 3m long holding tank from a boat EVER AGAIN! ). Most tanks have a hull-side vent so, in theory, you might be able to create a draw through the rinse-out fitting, though this depends on the way the water is let into the tank. If its just a hole, then fine- if its a nozzle, as it should be, then it may be harder. Getting air through, by the way, is an important part of composting toilets working. A wind powered fan might work- or you could fit a fan inside the hull-drawoff vent, but when pumping out you would have to leave the flap open (or turn the fan off!). Anyway that gets the air moving would work. I once considered an airline from an aquarium air pump into the tank....! I think that was a cider moment though!

Thanks The worse thing is breathing it in.... like when pulling the pump out hose from the fitting.... I speak of bitter experience on that!

Having been testing several treatments over the last year (not a job I recommend, as I was taking samples for analysis in my lab....!), I can state that the yeast treatment isn't really effective, especially in a large tank. The anerobic conditions in most large holding tanks means that the yeast, in theory, should make alcohol. However, we found that they didn't actually reproduce much- the cell count was quite low- much lower than I would expect. It may work in a cassette, but not really likely. Yeast prefer to feast on sugars, rather than fibreous material (the solids!) and urea / proteins (wee!). Most decomposition is by nitrosomer/nitrobacter bacteria. One of the main reasons for adding formaldehyde-bases chemicals (for which there is a British Standard) is to make the effluent less nasty to handle. If you pump out a tank or pour a cassette, where potentially pathogenic microorganisms are developing (i.e. not treated), you stand a chance of breathing in / getting covered in the (almost) invisible aerosol...... not a nice thought! Some boatyards won't empty a tank that is not treated, for that reason! The "green fluids" are usually based on bacteria that reproduce to overcome any pathogenic ones..... or use surfactants to break down the waste and cover the smell. If you want to ensure they work, then you need a good flow of air through the tank- a vent in and a (solar) powered fan on the outlet would ensure that they work better. And giving a good flush through on emptying. That also can remove the rather nasty pong (based on sulphur compounds being release in anerobic-without oxygen- conditions). Hope that adds to the debate!

Go away for 2 days on a school residential, and Hooly gets found! Well done to the boss for getting a pic though! Hope that she is back in the fleet soon- well done to Middlewich and everyone else!

It would be a good idea if between us we could "do" a length of canal- say 5 or 10 miles each. if we planned it right, we could cover a large part of the network simultaneously! I can cover the Hudds narrow and broad this weekend, but think Holly won't be up here! Hope everything is OK at Middlewich and you are not overtly stressing- and that the rest of the season is going to plan! Mark

I thought he went down Hatton (having passed Kingswood Jnc) or did I get that wrong?- so would be heading for the oxford (north and south) or GUC all points south. Though, the lift bridges on the Stratford are OK to do single handed- I have a few times. Just need patience, no wind and lots of rope. Oh, and hoping no one comes to use the bridge while you are faffing about! better than on the Leeds and Liverpool mind! Actually, think I am going mad- of course he is going south- he passed Hockley Heath... think I need to go to bed- brain hurting. Sorry!

WW certainly knows- Richard keeps a close eye on things. Probably Kevin at CB does (Martin Dugdale will certainly be watching this). It will only just make it into the June issues of either mag though- be nice if it could be resolved before deadline day!

He might have just gone off the rails- an earlier comment about Reginald Perrin seems quite apt. Perhaps he just needs time alone. He might be escaping goodness only knows what, from home, work, etc. Or he might just be an accomplished tea-leaf.... (or at least having a go). We shall have to wait and find out. No sign of him on the Hudds narrow yet- though might pop over to Sainsbury's and check the moorings again- and buy something nice to eat along the towpath (any excuse). M