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Stones to use in wildlife pond
Dicemanc
Posts: 40
Hi,
I am in the process of building a wildlife pond and, as one side will be adjacent to a small seating area, I would like it edged with stones.
My favoured stones, based on size and colour, are the Highland Grey Rockery Stone (http://www.gardenoasis.co.uk/highland-grey-rockery-stone-pieces-p-2104.html) - however the description on this website says these stones are "not fish friendly".
I believe (although I may be wrong) that this is because of the high natural ph levels in the stones.
Does anybody know if the "not fish friendly" warning also applies to wildlife in general, or is it particular to fish - ie could my potential frog, newt etc visitors be harmed if I use these stones?
Many thanks,
Col.
0
Posts
I know what you mean - who thought choosing some edging stones could be made so complicated!
I sent them an email three days ago, but haven't had a response yet - hence posting on here. I'll give them a few days and then call them (unless someone on here know the answer in the meantime).
If I do get a definitive answer I will let you know...
Col.
Could it be that they leach something into the water Col?
Seems a bit odd though...wouldn't have thought they could damage wildlife in any significant way.
Probably a Health and Safety issue concocted just to cover themselves...
I live in west central Scotland - not where that photo is...
Where do you live Col? Those stones would look really out of place in my fenland plot
In the sticks near Peterborough
Fairygirl - my local garden centre thought it might be something to do with the natural alkalinity of the stones raising the ph level of the water, although he admitted that was an educated guess rather than knowledge.
Nutcutlet - I'm in Birmingham - the only other natural stone around here is red brick
These stones are the best ones I could find that match the colour of the paved seating area - so hopefully they'll be ok.
That was the only thing I could think of Col, but I expect it would have to be a huge amount of rocks and a very tiny pond to make a difference!
They look just like the ones I inherited here - which are forming a planting shelf in my new tiny pond...
I don't have any fish though
Must take a pic of it now that the plants are in
Just a thought - as it's a wildlife pond you're making, you may find the fish eat all the wildlife - unless it's a very big pond and can stand the competition.
I live in west central Scotland - not where that photo is...
Thanks Fairygirl - very impressive. Those stones look the very similar to the ones I'm looking to buy.
Sorry I didn't make it clear - I won't be having any fish in the pond, but I thought if the stones aren't suitable for a fish then it seems possible they they wouldn't be suitable for general wildlife either... (I was rubbish at biology at school - but it seems likely that if something can harm a fish then it would harm a frog as well?)
Having said that - the website only mentions fish. You'd have thought it would mention other animals if that were the case...
I don't think there's much to worry about Col. I've had rocks like these in a few ponds , they were all full of wildlife, and at my last house we had lots of fish too - it was a big pond so plenty of room for everything.
I'll let you know if everything dies in this one though...
I live in west central Scotland - not where that photo is...
I've had an answer from the supplier of the Highland rockery stones and they have advised that they would not recommend its use in any pond due to "lime or other impurity in the rock that would contaminate the water making it unsuitable for any kind of wildlife".
They say that 3 out of the 13 types of rock they sell are unsuitable - so it seems that the majority of rock is safe to use, but a sizable minority could cause problems (according to this rock supplier).
It could be that, as Fairygirl suggests, they are covering themselves from Health & Safety perspective - but as I haven't bought them yet it is probably safer to have a rethink and buy one of the safer types.
Col.
Loved this bit - "Please note that due to high regional delivery surcharges imposed by the haulage company we are unable to deliver this item to Cornwall, Highlands, Moray or Aberdeenshire using our free delivery service."
So what exactly is Highland Grey stone then
. I guess they only mean the colour.
Looks like it is a form of limestone. Found this on the web which seems sensible advice
Limestone, too, is commonly found as rocks of waterfalls and pond edges (but these rocks are not particularly flat unless very large or cut that way), and as decorative elements when large examples are positioned in or near the pond (the irregular, weathered field stones). Some limestone varieties (the massive limestones) will hold up quite well while sitting in water (and will actually help buffer acid contributors to the pond – keeping the pH between 7.0 and 8.5); whereas, other varieties (the crumbly limestones) will leach lime into the pond and will increase the alkalinity of the water. An alkaline pH of greater than 9.0 will spell doom for fish; needing the removal of sources of alkalinity or chemical correction. (With regard to high pHs, any concrete, concrete blocks, and mortar used in the construction of a pond should be treated with lime neutralizers or a non-toxic sealant to avoid leaching lime into the water.) A close cousin to limestone is dolostone (formed of the mineral dolomite). This particular rock form of calcium carbonate will not likely increase the water’s pH. Within our pond, dolostone blocks are used in the walls that form several sides of the pond, sticking out above the water level and extending to the bottom.
I intend to use paddlestones when I build my wildlife pond, as another member used in theirs...