pH vs TDS

pH vs TDS

PH, quite constant except for tap water. TDS, A sharp decrease from GT to CS1 where it gradually decreases until CS4 then gradually increase all the way until Pond, then a slight decrease at tap water.

What is the main cause of this?

The optimum PH level required for the healthy growth of plants is PH 6-7, which is seen in the case of CS1 all the way to the pond. As for Why the GT has a PH of 6.64, this is because of the usage of soap and detergent which are alkalis. As for the tap water with the PH 7.47 , limestone deposits contribute greatly to the alkali levels.

TDS Highest TDS observed in GT due to the presence of grease, oil, cosmetics.

Why the gradual decrease from CS1 to CS4? As CS1 is where the water from the GT just entered, it is where the most polluted water is, in the entire C shaped container. As the water flows to CS2, CS3 and eventually to CS4, it has already undergone the ‘cleaning’ process and thus, the water at CS4 is so much cleaner than compared to the water at CS1.

Why the gradual increase from CS4 to Pond? It is highly possible that its due to the fast motion of the flowing water from the outlet to the pond, the solids get dissolved easier.

Why the sudden increase at tap water? As Tap Water is filtered, thus this greatly decreases the TDS content in the water.