Re: urgent need help
When you adding blackwater extract ,you re decreasing the pH level , but then you add salt ,you rise it again back to starting level.
Somehow (correct me if i'wrong) salt also rise buffering capacity of water so it s very hard and difficult to reduce the pH level.
My suggestion , change your water ( sedimented rain water is ussually had lower pH (even slight acid) and low gH also ) but carefull not to use rainwater from near industrial poluted area. Or use water from purified drinking water filter which is using reverse osmosis system or Ion Exchange system ,the processed water is easy to get lower pH and very stabil buffering capacity , so your pH level will not plays up and down.