Having recently built our first pond,3000 gallon capacity,I am after some advice as a beginner. The pond has a 20ft stream/waterfall into two joined ponds,the stream is concrete but has now been sealed,the ph is at present 9. Is this suitable for fishkeeping,and if so what types would you recommend? If the ph is still too high,what would be the best method to lower it. Prior to sealing the stream,the ph was in excess of 10,so it has reduced (a bit) Thank you
The ideal ph is 7 to 8 especially for KOi. Fluctuations up to 11 are not uncommon and should not hurt the fish. Goldies are tried and trusted and hardy. Watch out for Orfe as they are sensitive to poor water .
Apart from sealing the watercourse what do you have in the pond? Concrete slabs etc will increase the ph so consider getting rid of them and using something that will not effect the chemistry.
More important than ph I would suggest is ammonia / nitrites / nitrate levels. These are the ones that will do the real damage especially the first two.