My block pond build

[kendragon]

You may have to etch the concrete if the pH doesn't come down.

 

[davemal]

I think the newer blocks are pushing salt through the tanking and that is pushing up the ph. Or I never fully sealed the lowest part of the pond so water is pushing through the bottom of the pond coming through the blockwork. Drain it down and try again … this time I have learned though.

 

[kendragon]

Sounds like you already know about the leeching of lime from concrete.

 

[davemal]

yes but in other ponds I have done tanking blocks it … mine is bigger as to my cost I have rushed a bit. Stupid but lucky its mine not a customers.

 

[davemal]

I will use old pond for now and work on new one then refill and test for 2 weeks

 

[kendragon]

Plastic ponds have just the opposite problem (crashing pH).....nothing is perfect.

 

[davemal]

plastic wont work for me … if tanking fails to work something like g4 pond paint might be next. The one thing I don't want to have to do is fiber glass...

 

[davemal]

Done some tests …. if uncured tanking causes water ph to go upto 12.6 !! after 24 hrs it goes upto 10.4 . Hope as it cures it drops lower. KA told me it was safe to fill after 24hrs cure time, if constantly wet I don't think it totally cures so I will fix water leaking in then retry. Got the water entering the pond down to half a bucket a day so wont take long. Hope to reseal and retry soon but will fill 2 feet at a time this time. Also I want to plant (hard with large carp) as plants will help keep ph down. Late in the season but I will add water lilies with large rocks around roots to stop carp digging.

 

[davemal]

Come up with an idea to plant water lilies in the pond so the carp cant dig and move them … planting basket will have large pebbles ontop of it. Holes in sides should let tench and small gold fish hide and get some quiet away from bigger fish.

 

[davemal]

after a month ph is 11.4 found out I should not have put feb in cement. Tanking pushes it out to surface 2 50% water changes and water is 9.9 so hope it wont go up too much then change more.