STRANGE MARKS

[mandy]

Hello there
This is my first year renting out my house in France and I've had lots of tips from this forum, so thank you all very much. I've just been over to get the house ready and noticed some rust like marks on the bottom of the pool liner which wont come off. Every day there appear to be more. They are about 1/2cm long and very irregular. I wondered if they might be something that is airborn and which smudges , Any suggestions as to what they may be and how to prevent them gratefully received.

[vrooje]

Is it possible that they're marks from leaves or something like that?

There are Eucalyptus trees near my parents' pool, and the leaves are acidic and stain the pool when they fall in. They make distinct leaf-shaped marks, though.

I'm totally speculating -- as my parents' pool is in California, I have no idea how that translates to plant life in your area.

[mandy]

Thanks for your reply. I'm starting to think that the old walnut tree near the pool may be responsible. I have found out that you can make dye from the bark and leaves, as well as the husks. Also I am wondering if there is a particular insect that eats walnut products that would have the dye in it when it drowned in my pool. We do have a lot of bugs round here. Any experts out there?

[Ciapolin]

I know from experience that walnuts stain badly - they make a digestivo hear from them (called noccino) and my first attempt resulted in hads that looked like I had smoked for years (I haven't!).

It's the juice from the green husks that is the problem. Have you had any windfalls into the pool?

[enid]

We make the same digestif called vin de noix here - this is our third year of making it and this year at last I managed to do it with minimal nail staining - I do wear gloves but the walnuts are lethal. The first year I made the stuopid assumption that as the nuts are green when you prepare them they wouldn't stain - like you Ciapolin was badly marked - I spent weeks with my hands curled in fists at social events or feeling the need to explain every time I saw someone's eyes flick to my less than pretty fingernails.

Re the marks I think I would seek specialist advice through a pool supplier in your region who may have a product that will help. Good luck!

[Alan Knighting]

Mandy,

Your problem is almost certainly caused by leaves dropping from your walnut tree. They do stain the pool. Remove any leaves as soon as you see them and brush any stains. Any residual marks should disappear within a day or two. If dealt with promptly they are unlikely to be permanent.

There is a possibility that the stains are in fact black algae. If so, very regular brushing and the use of a commercial algaecide should get rid of them.

Alan

[mandy]

Thanks for the advice - I'll pass it on to the guy looking after the pool now we've returned. Crossed fingers it will work!