Comments on: Slimy brown scum – it has a name

By: Rod Kane

Rod Kane — Wed, 21 Nov 2018 00:38:25 +0000

Last year after doing some research on google I sprayed it with Calcium hypochlorite which is granulated pool chlorine.
You can get 10kg of this off trademe for about $65. I mixed up a heavy solution in a 10L bucket using about 1kg and this made about 30 litres of spray which I put into a backpack sprayer. I waited until we had rain and the horrible stuff was hydrated and then hit it. It definitely worked. It started to kill it soon after it started to dry out and a month or so later there was little evidence of it.
Having said all that, when I left for Aussie in April there was no sign of it, when I came back in October the drive was a mess again. So I have just repeated the treatment and will see what happens over the next month. My drive is close to the Hokianga harbour..like about 30 metres away and it is all metal, however I did the rail trail up there on the weekend and that is infested with it too. This seemed to work but it will be an on-going battle. i will also try the copper sulphate as that is not expensive if you buy 25kg of it.

By: Rae Roadley

Rae Roadley — Fri, 26 Oct 2018 03:13:33 +0000

I’ve got no idea – but maybe. I wouldn’t suggest making a meal of it. Glad you dogs came right.

By: Sue Beardslee

Sue Beardslee — Mon, 03 Sep 2018 18:59:37 +0000

Our 2 small dogs were seen eating it. Both now have intestinal upsets. Could this be caused by it? I sprinkled baking soda on it and it is now gone.

By: JOHN Berry

JOHN Berry — Sat, 16 Jun 2018 01:23:18 +0000

I used a propane torch on mine and that works fine

By: Rae Roadley

Rae Roadley — Fri, 18 May 2018 02:20:15 +0000

Thanks for this.

By: Emma

Emma — Tue, 01 May 2018 05:18:36 +0000

Hi – last year after reading this blog I tried the option of 1kg of washing soda dissolved in 10L of warm water, applied with a watering can. It works — but only if you use the white powder type of washing soda, not the clear crystals. I buy the powder type in a green bag from Countdown in Warkworth.

I apply it fairly liberally when the algae is all soft and rubbery after a rainfall. Within a couple of hours it starts to turn from green to yellowy-green and there is an quite an unpleasant smell in the air. Sort of bleach like, with a seaweed aftertaste.

Within a couple of weeks the slime will disappear. Most of the gravel driveway around our house is free of large amounts, but it does require semi regular upkeep as bits come in on tyres and recolonise the area. I’m still treating the rest of our driveway, about 200m, and hopefully one day soon we’ll have it mostly under control.

By: Andy Sealey

Andy Sealey — Sun, 25 Feb 2018 08:17:23 +0000

I recently moved and into a house with a lime chip driveway. As soon as it got wet I ended up with vast mats of this horrible unsightly Nostoc. I can confirm that I have successfully used copper sulphate for the control of Nostoc. Nostoc is a bacterial colony and copper is a natural bactericide. I just sprinkled it on after it had swollen in wet periods. Dissolved in water will also work at rates between 30-50gm / litre.
Copper is so effective in controlling bacterial that it is now being used in Hospitals in other parts of the world. Taps, door handles, push and kick plates and other areas with a 90% reduction in post operative infections and MRSA.
Best place to purchase is at Farmlands for $22.00/1.5kg (as at 25/2/18) Farriers will also stock it as should Wrightsons PCG

By: Andrew McLaren

Andrew McLaren — Wed, 29 Nov 2017 07:01:49 +0000

We are in the Kaipara Flats area, and have had success with spraying with a copper sulphate (bluestone) solution. The idea was that its basically an algae, and algae’s don’t like copper!

My trial patch was when the nostoc was fairly dry, and sprayed it with a hand sprayer at 20g/litre. Nothing appeared to happen for a number of weeks, but suddenly realised that it had almost disappeared from the test area.

For the drive (around 400m) and gravel around the house, I did 200L at 30g/litre. The normal sprayer does around 200L/hectacre, but probably a bit higher dosage than this as took it slow. When applied this time the nostoc was still damp, but no longer swollen.

The surprise here was the next couple of days, which smelt like a trip to the seaside – I imagine it was the smell of rotting seaweed that was familiar. Its now 2 months later, and the nostoc is still visible, but noticeably less, and doesn’t swell up at all in the rain. I’m hoping that’s the end of it.

Copper Sulphate is readily available at garden centres at a price, but places like Wrightsons do 25kg bags at just over $100. Its pretty safe, but would be careful with livestock – I think from memory horses are sensitive to copper poisoning, so would keep them away from the edges of sprayed areas.

Hope this helps. I’ll keep you posted!

By: Jim. Black

Jim. Black — Sun, 29 Oct 2017 02:00:13 +0000

Hello. We’ll have nostoc. commune on cold tar asphalt drive. I have spayed for weeds with glyphosate. Has anyone tried potassium permanganate. Condys. Chrystal. As a spray. Came across reference in turf management talking about black slime on golf course greens. Am going to try. Sorted. Moss mould. See how it goes.

Jim. Ramarama

By: Geoff

Geoff — Sun, 30 Jul 2017 22:41:34 +0000

Hello Peter

I believe the C3 cleaner is a similar product to the XY-12 Sodium Hypochlorite that you used. It does not have a chemical name as such. It is described as Chlorinated Cleaning Chemical and contains 140g/L available chlorine with recommended dilution of 3 parts water to 1 part C3.
3 different uses are promoted
a) correction of dairy plant grade faults
b) makes water safe
c) kills moss,mould and algae

Cheers
Geoff