When watermakers go bad
Watermakers have gone from being a pernickity, high-maintenance gadget to an essential domestic appliance
It isn’t just the ‘blackwater’ that can create unmentionable nastiness. Lindsay Ross of Fischer Panda explains, ‘if you have ever had occasion to open up a watermaker system on a boat that has been left with sea water sitting in it for a year or more then you would not forget it.'
He adds, ’The water goes black with marine growth and the smell is the foulest of foul - a heady mixture of decomposing organic matter resulting in the correct ingredients for the primeval soup – CO2, methane and ammonia.’
He adds this build up of marine growth is the reason that watermakers need flushing through with potable water regularly. Prior to the onset of automatic fresh-water flushing the only way of preparing for periods of absence was through 'pickling' the membrane. This meant filling up the membrane vessel with a sodium bisulphate solution to inhibit any organic growth. Unfortunately, this kind of treatment also tends to shorten the life of the membrane…
So, the automated fresh water flush has made on-board watermakers a viable option for all kinds of boaters. Fischer Panda’s HRO and Sea Recovery units give a range from 27l/hr to 7,000l/hr, and both benefit from this automatic back-flushing of the membrane with product water every seven days as a useful ‘holding pattern’. Charcoal and ultra-violet filters are also available for absolute assurance of odour and bacteria-free water quality.
Mr Ross adds, ‘The units have gone from being a pernickity, high-maintenance gadget on boats run by cruising yachtsman covering long distances, to more or less an essential domestic appliance that means yacht designers can maximise both performance and living space onboard by reducing tank space. The user can make water as and when they need it – or leave it without wondering what’s building up inside.’
Jim Cudd of Furneaux Riddall explains there’s more ways than one to stop the bugs having enough fun to colonise the watermaker. Spectra’s Z-Brane system works by exposing inward water to an electrostatic field, charging all water molecules in a positive orientation. These charged surfaces form a strong boundary layer preventing particles from bonding. This means bacteria are rendered inactive and unable to absorb nutrition to replicate into colonies. This prevents the formation of sludge, scale and biological fouling.
However, Mr Cudd explains, as it only takes a miniscule draw from the battery, you can happily leave the boat for an extended period and keep the bugs at bay.
On the same subject, Spectra's BioGuard is an easy-fit antifouling system designed for marine air-conditioning systems. It is an in-line filter which keeps pipes, hoses and heat exchangers free of marine growth and barnacles even in warmer climates as field tests in Florida have proven.
Further, since no electrical connections or control systems are necessary and the unit is installed straight into the cooled water supply line, it is particularly easy to put in place. Once there, it is also easy to keep an eye on through the clear housing. And when it needs replacing, changing the alloy module only takes a few minutes.
So, keeping the nasties at bay is getting easier all the time.
Images for this article - click to enlarge
Unless otherwise stated, all images copyright © Mercator Media 2012. This does not exclude the owner's assertion of copyright over the material.
