High PH in Rubbermaid tubs

[Goosedub]

Hey. This is very concerning. I had some fish in my tubs and they were doing fine. This weekend my pond plants finally arrived. I potted them in dyna dirt and hung them in the pond. I put some bricks from my basement (not the cleanest place in the world) in them to prop up a couple pots. I then added the rest of my rice fish to one tub and white clouds to another. I have found several floating in the tubs in the past day. Tested the water and this is what I got. What could have cause this and what should I do? 

[Colu]

It could be something in the bricks raising your pH kH and GH I would remove them and do small water changes to gradually get your pH back to your normal range @Goosedub