Travertine - Algon

[LyndaG]

I used Algon on my travertine patio for a light green algae but it has stained it patchy brown/black. After reading this site I checked the 'ingredients' and it is ascetic acid so I contacted Algon for advice as the pack only says don't use on marble. Their reply is basically that they only state marble because that covers all that type of material (not being a geologist, I'm not sure how I was supposed to know that), and that the staining is black mould that was hiding under the green algae which now needs a fungicide to treat. Am I to believe this or is it the 'dreaded acid' that has done the damage? I'll try attaching a photo. What can I do?
/Users/lyndaclark/Desktop/IMG_0669.jpg

[lutonlagerlout]

Lynda you need to upload the photo to a file sharing site
we cant look at your desktop
roger is that man for this and no doubt will be along later
cheers LLL

[LyndaG]

Here's a pic..
https://www.dropbox.com/s/3gd8o26aporpybd/IMG_0669.jpeg?dl=0

[RAPressureWashing]

If you could upload a photo so I can see what has gone on here, I have an idea but would need to see a photo before commenting.

[LyndaG]

Here's a pic on Dropbox
https://www.dropbox.com/s/3gd8o26aporpybd/IMG_0669.jpeg?dl=0

[RAPressureWashing]

Are you sure you have spelt the acid used correctly ? as I don't know this one. Acetic Acid is basically vinegar.
Anyway had a look at the photo and you should be able to clean this up pretty easily might take a couple of go's though as you have quite a bit of Lichen staining, if you go to this page on the main site http://www.pavingexpert.com/stains.htm and scroll down to the berries & fruit solution, this should rid your surface of all the problems I see in the photo, you might need to strengthen the mix up to 2:1 (2 parts water 1 part Chlorine) and allow a longer dwell time say 30 mins.

Here's a Travertine paving quite similar to yours


And after cleaning with the above mix

[LyndaG]

Thank you so much, I had not found this part of the site. I will give it a go. I had not noticed this dark staining before, so is this mould or an acid reaction? I did misspell it by the way, and realised it was basically just vinegar when I looked it up.
Lynda

[RAPressureWashing]

Thank you so much, I had not found this part of the site. I will give it a go. I had not noticed this dark staining before, so is this mould or an acid reaction? I did misspell it by the way, and realised it was basically just vinegar when I looked it up.
Lynda

What the algon has tried to do is kill off the algae, and from the photo looks more like it hasn't been cleaned off properly. Is this one of those spray on and walk away type cleaners?
Anyway, try the cleaning solution on the link I put up, just follow it to the letter and you really shouldn't have any problems. Just watch your run-off areas IE grass. tender plants etc as it can damage these. Any more info needed, just ask.

[LyndaG]

I followed your advice and it has worked really well, thank you. There are a couple of places that need doing again but generally the treatment has made a huge difference. And yes, it was a 'spray on and walk away' type product. Thank goodness I found this site!