Look at the state of my poor old pond. After 15 odd years, water has got between the capping stones and the liner, blowing
the render and allowing water to seep through and algify.
I've tried digging out the render at the top and replacing, but its just come back again.
I think I know what I've got to do, remove the capping stones and fold the liner back up behind and over something.
As you can see from the photo, I've only got a bit of liner to play with (hopefully the same all round).
The problems I can see are ;-
Whatever I put the liner around wont be cemented in place, and must be inert
If I put the capping stones back on I wont be able to grout in between them without getting mortar all in the water.
Any ideas?
Cheers in advance, I'd like to get the pond back up to scratch this year before I lose all interest.
Stacey
I think I agree with deadog, lower your water level a couple of inches asap, because I would say the the main cause of the algae growing on the outside of your pond, is because the grouting under your capping stones is letting water through. By lowering your water level a bit, you would stop any more water getting under your capping stones, which in turn will stop your algae staining from getting worse on the pond wall.
You wont harm your liner by exposing it to light/sunlight, I`ve had 6inches of exposed liner on my pond for a good 20 years now, and its still ok.
For a permanent solution to the algae, it`ll take a bit longer. Firstly, you will have to remove the capping stones that are above any algae patch, and chip off any cement that is on them. Then, you will have to leave them to dry out a bit, as they will probably be soaking wet, and you want them a bit cleaner and dryer before you re-fix them.
While you are waiting for the sun to come out and dry everything out, is the perfect time for you to scrape as much of the algae off the walls as you can, and then scrub the walls with an algaecide solution (builders merchant/ b&q) to kill all the algae spores and make everything nice and clean again.
Once you are happy that everything is done, its time to put the copings back on. You could cement them on again, but if it were me, I`d just use silicone. A couple of bands of that, about an inch in from the water side and the outside of the pond, and gently lay the coping down. Press down till you are happy with them,, and you`re done!!
ps, one of the benefits of using silicone is that it is easy to use and is waterproof, so no water will be able to creep under your capping stones, whereas cement is pretty messy and NOT waterproof. I suspect that when your pond was built, the coping cement wasn`t treated with a waterproofer, and its been slowly leaking away under them for years.
