ORIGIN OF GREEN SLIME ON DECK AND RUNNING RIGGING

[alisdair4]

I (like many forumites, I suspect) have spent much less time on my boat this year than I would have liked. As a result, when doing sea trials (new gearbox - it's a long and expensive story) yesterday, we were on board for the first time in several months.

Nordlys was manky - green slime on the decks, coach-roof and all over any lines which had been lying on the deck. Two hours with my pressure sorted the former, and the sheets and control lines are now in the bath (much to SWMBO's annoyance).

Thus, I have no difficulty dealing with the symptom - I merely wonder what the cause of the green slime is?

More importantly, other than scrubbing your decks down every week, is there a cheap and effective way of preventing it?

 

[Cowie]

I (like many forumites, I suspect) have spent much less time on my boat this year than I would have liked. As a result, when doing sea trials (new gearbox - it's a long and expensive story) yesterday, we were on board for the first time in several months.

Nordlys was manky - green slime on the decks, coach-roof and all over any lines which had been lying on the deck. Two hours with my pressure sorted the former, and the sheets and control lines are now in the bath (much to SWMBO's annoyance).

Thus, I have no difficulty dealing with the symptom - I merely wonder what the cause of the green slime is?

More importantly, other than scrubbing your decks down every week, is there a cheap and effective way of preventing it?

Fresh water in the atmosphere and water accumulation on surface areas, good one for the control lines is Daz washing powder, great on the deck as we,

 

[Gwylan]

Assume it is the moisture and not being moved allows some algae or similar to prosper.
Solution that works for me is Patio clear or whatever. Dilute, spray everything and leave.

 

[Sandy]

It is algae. A good wash with a BIOLOGICAL washing powder will work wonders.

 

[alisdair4]

It is algae. A good wash with a BIOLOGICAL washing powder will work wonders.

Thanks all,

Just so I am clear - the biological powder serves as a preventative? I've often used washing powder to clean the decks - hadn't realised it might also be a preventative.

 

[Bodach na mara]

I don't know about biological washing powder but I have had advice to use a stuff called Wet and Forget which prevents algal growth. Another product is Patio Magic.

The source of the problem is that the air is now too clean, with none of the old sulphur or acidic pollution and it is also allowing too much sunlight which encourages organic growth. It is also failing to kill the blackspot on my roses. So the benefits of longer life and less incidence of respiratory problems come with the small problem that you are experiencing.

 

[Spirit (of Glenans)]

I don't know about biological washing powder but I have had advice to use a stuff called Wet and Forget which prevents algal growth. Another product is Patio Magic.

The source of the problem is that the air is now too clean, with none of the old sulphur or acidic pollution and it is also allowing too much sunlight which encourages organic growth. It is also failing to kill the blackspot on my roses. So the benefits of longer life and less incidence of respiratory problems come with the small problem that you are experiencing.

+1 for Patio Magic. Apply at a ratio of 4:1 anf forget for sox months.

 

[alisdair4]

I don't know about biological washing powder but I have had advice to use a stuff called Wet and Forget which prevents algal growth. Another product is Patio Magic.

The source of the problem is that the air is now too clean, with none of the old sulphur or acidic pollution and it is also allowing too much sunlight which encourages organic growth. It is also failing to kill the blackspot on my roses. So the benefits of longer life and less incidence of respiratory problems come with the small problem that you are experiencing.

Thank you! This is very much a " first world problem'! I shall try Patio Magic.

 

[Slowboat35]

PLEASE DON"T! ​

 

[Spirit (of Glenans)]

PLEASE DON"T! View attachment 104905​

A few years back this forum frequently had posts discussing the addition of hot chili powder to antifoul, but from what you have attached it would seem that Benzalkonium would be the obvious additive.?

 

[Bodach na mara]

I take your point about toxicity, however the same applies to antifouling! With Patio Magic and similar products however we do not put them in the sea, we spray them on deck and on ropes and covers, usually on a dry day and in amounts that would be similar to if we were spraying whisky.

It's expensive stuff ye ken and not to be wasted. Run-off to the sea is definitely something to be avoided.

 

[NormanS]

PLEASE DON"T! View attachment 104905​

Yes of course it is, otherwise it wouldn't work. However in use, it's diluted and applied sparingly. All that is required is to wet the surface with the diluted product. It's not as if gallons of the stuff were being poured into the sea.
There are various makes, Patio Magic is probably the best known and probably the most expensive, but other makes are available, with names like Spray and Walk Away, or similar. I have found a wide variation of prices for basically the same product.

 

[Slowboat35]

I simply can't believe the wanton irresponsibility of what's been written above.

That warning's written in plain enough language - anti foul is intended for marine use and certifed as such, how can you mke such an idiotic comparison?

You suppose it doesn't run off in the rain?

Fugg me backwards! Yachtsmen indeed!

 

[Irish Rover]

The discharge of any form of detergent in the sea is absolutely prohibited here in Turkey. In my marina there's always someone around to complain if they see any suds or bubbles around your boat. The marina staff invariably appear warning of huge fines from the coastguard if they spot it. They don't distinguish between fairy liquid bubbles and bespoke "environmentally safe" boat wash.

 

[NormanS]

I simply can't believe the wanton irresponsibility - nay, criminal irresponsibility of what's been written above.

That warning's written in plain enough language - anti foul is intended for marine use and certifed as such, how can you mke such an idiotic comparison?

You suppose it doesn't run off in the rain?

Fugg me backwards! Call yourselves yachtsmen?

I think you're getting a wee bit too excited. If the stuff was as dangerous as you're making out, it wouldn't be available to buy. It has already been explained to you that the method of use merely involves damping the surface. Your predilections regarding "fugging" are probably of little interest to us, but, 'whatever turns you on'. ?

 

[SailingDog]

I simply can't believe the wanton irresponsibility - nay, criminal irresponsibility of what's been written above.

That warning's written in plain enough language - anti foul is intended for marine use and certifed as such, how can you mke such an idiotic comparison?

You suppose it doesn't run off in the rain?

Fugg me backwards! Call yourselves yachtsmen?

Where should we be drawing the line, we utilise a lot of products which if used incorrectly have the potential to do harm. Wet&Forget is a product aimed at the algae issue in the marine sector albeit expensive. What about weed killer and other insecticides they all have potential downsides.
The Op has an algae problem and needs an affordable solution I'm trying W&F the jury is still out on how well it works.

 

[ip485]

Patio Magic works well, but it is indisputable it is toxic in the marine enviroment. I would guess (but dont know) in the dilutions that would enter the sea from recreational use its impact would be very small and it would degrade quickly, but perhaps someone can point to any research.

I am afraid I have used PatioMagic, and it is very effective.

I think there is a better alternative, which from a quick review, may be less toxic - Borax. This is the ingredient used in the proprietory solutions for spray teak dissolved in ethanol. It is at least as effective as PatioMagic in my experience, and I think lasts longer. It can be purchased cheaply as a powder and dissolves in water. In ethanol I suspect it penetrates better, especially on wood, but ethanol has it hazards in the marine enviroment.

I stand to be corrected that Borax is more or less toxic.

My own view is proportionality is the key. Even modern antifouls are toxic, the question is how Patio Magic compares and the amount that is likely to enter the sea and how long it hangs around. The same is true of Borax.

 

[stevebrassett]

Apparently Borax is not available in the UK. I won't provide quotes, but a quick Google will reveal all.

 

[pvb]

Patio Magic works well, but it is indisputable it is toxic in the marine enviroment. I would guess (but dont know) in the dilutions that would enter the sea from recreational use its impact would be very small and it would degrade quickly, but perhaps someone can point to any research.

I am afraid I have used PatioMagic, and it is very effective.

I think there is a better alternative, which from a quick review, may be less toxic - Borax. This is the ingredient used in the proprietory solutions for spray teak dissolved in ethanol. It is at least as effective as PatioMagic in my experience, and I think lasts longer. It can be purchased cheaply as a powder and dissolves in water. In ethanol I suspect it penetrates better, especially on wood, but ethanol has it hazards in the marine enviroment.

I stand to be corrected that Borax is more or less toxic.

My own view is proportionality is the key. Even modern antifouls are toxic, the question is how Patio Magic compares and the amount that is likely to enter the sea and how long it hangs around. The same is true of Borax.

I use Boracol, which contains disodium octaborate (a fungicide) and benzalkonium chloride (an algaecide). It has an ethanol base, so penetrates well into wood. I used it on the teak on my last boat, a Hallberg-Rassy 352, as well as on canvas. I use it on the sprayhood of my current boat. The amount applied is miniscule in the overall scheme of things, so fears about harming marine life are unfounded.

 

[iamtjc]

Patio Magic works well, but it is indisputable it is toxic in the marine enviroment. I would guess (but dont know) in the dilutions that would enter the sea from recreational use its impact would be very small and it would degrade quickly, but perhaps someone can point to any research.

There is a lot of research on Benzalkonium Chloride, much of it hard to get to grips with.
This site is more approachable than most.
American Society of Microbiology

Given data in that report, I did some very rough calculations.
Let's say you use 1 litre of Patio Magic which I'm told is 7.5% BAC
The site above says that 0.004 mg/litre is toxic to a shellfish.
That is the 1 litre of PM diluted into 18,750 litres of water.

So it isn't a trivial pollutant. We (globally) make over 250,000 tonnes of it annually a good deal of which ends up in our waterways via all manner of disinfecting products.