Fertilizers suitable for RO water

[MateoinLosAngeles]

Some popular orchid fertilizers have their "tap" version and their "RO" one. Others, however, don't make any notes about whether they can be used with RO water without massively decreasing the pH.

Are there trusted brands of soluble fertilizers (let's skip MSU and K-Lite as we know those work) that can be used with RO water?

In my experience, Dyno-Gro acidifies the water a lot and I would assume it's a no-no. I'm not sure about Jack's or Peters.

[estación seca]

The pot contents dramatically affect the pH of whatever winds up in the pot. Ray has written to check the pH of what flows out of the pot before making changes to the inflow pH.

[Lil Duck]

Originally Posted by MateoinLosAngeles

Some popular orchid fertilizers have their "tap" version and their "RO" one. Others, however, don't make any notes about whether they can be used with RO water without massively decreasing the pH.

Are there trusted brands of soluble fertilizers (let's skip MSU and K-Lite as we know those work) that can be used with RO water?

In my experience, Dyno-Gro acidifies the water a lot and I would assume it's a no-no. I'm not sure about Jack's or Peters.

Why are you afraid of low PH nutrient uptake is highest in acidic PHs and a study has found that Phalaenopsis orchids geminate best at a PH roughly around 4.5. In nature the water dripping through mossy trees or running down from the canopy can be as low as 3.5. If you want to make sure that your plants don't start melting then I would just look at the amount of calcium and magnesium in the mix, they act as buffers to prevent the PH from falling too low.

[Ray]

The pH of the applied solution - by itself - has very little to do with the pH of the rhizosphere.