Ph dropping

[Mrwobbly]

I am running an automotive system withe a gravity fed reservoir my nutrients ans ph measures 5.8 and 1.8 but within a couple of hours of it going into the automotive the ph drops to 5.3 and ex rises to 3.2 can anyone help

[golfnrl]

By 'automotive' I'm assuming you mean automatic? If not, please let us know what you mean. That description sounds a bit like like an autopot system. How big is your reservoir? What's your grow medium? the 5.8 PH would be OK for coco. What are you using? Have you tested the PH of your water before adding your nutes? You should know that number. For me, tap water is 7.1. I'm adjusting the PH downward most of the time. Do you have to add PH up or down to get the PH to 5.8? BTW, what are you using to adjust the PH?

What does the 1.8 signify? Is that the EC of your nutrient solution? What brand/kind of nutrients are you using? Is your reservoir aerated? Using a small pump timed to run a few minutes a few times a day will def help stabilize the PH. I wouldn't use an air stone. I ended up buying a PH controller to stabilize the PH. When are you measuring the PH of your nutrient solution? Have you added all of your nutrients to the water before you test? Gives us some details.

[Bluey]

If the pH in your nute tank is not stable then you need to work out why.

I run an automated feeding/watering system here and have run into problems in the past with pH instability. It needs to stay at the same number between refills.

It is likely the nutrients and additives you are using are not compatible as it was in my case but it can also be caused by algae in your tank. If you are running a hydro setup with return then thats a different story and complicates things a bit more.

I no longer run an airstone as I don't need one and that only adds to the instability of the pH in the tank.

What medium are you growing in?