Bloom City Professional pH Up + Down Control Kit for Optimal Nutrient Uptake (Two 2.5 Gallon jugs) 640 Total oz

These meet the need perfectly. That said, it's critical to have an accurate Ph meter and, especially, to only adjust Ph in one direction by applying a small amount at a time when first starting out. It really helps to have a source of RO water to start with because true RO water is Ph 7.00. RO is also free of minerals and salts which can act as a buffer, rendering the Ph Up/Down solutions ineffective. Bottom line: These Ph Up/Down solutions are highly recommended provided a Ph neutral water source is used, an accurate and calibrated Ph meter is available, and Ph is only adjusted in one direction.

used these to lower soil pH of tomatoesmake sure to use gloves as these are a very high and low pH substance, read dilution instructions carefully!

Just a couple drops and my PH level was where I needed it to be. These 2 small bottles should last me more than a year.

I grow vegetables in a hydroponic setup and ph is crucial for healthy development. All I need is 1 ml in 6 gallons of water to change an entire point either direction. Well worth the money.

I really needed the ph down bc the waters oh was to high & it worked. I went ahead and got this one with the up and down bc you never know when you may need one or the other.

It does exactly what it’s supposed to unlike other brands I’ve used in the past. A little goes a very long way.

Box was already opened when I received it. That's a little invasive, I think. Other than that everything was okay.

Bought because made in the US and no dye is added. Only used once. Seems like the down is stronger than the up. Just need trial and error when it comes to the amount.