- Joined
- Aug 21, 2015
- Messages
- 2,064
- Reaction score
- 320
so i was having problems with my 713 hanna checker always reading 0 so i went to a lfs store and purchased the 736 ulr phosphorus by mistake cant take it back becuz i opened it and threw out the box is this good or do i need the 774 ulr phosphate checker