Properly adjusting pH and nutrients in series undercurrent RDWC

I have an eight system undercurrent RDWC system, plus controller. The controller bucket pumps into the first grow bucket via a 1/2" hose, and the rest of the buckets are connected in series with 1" hose. They are passively pulled back into the controller bucket, one by one, and recirculated again. I'm using an 80gph pump that cycles all of my water twice an hour, mainly for ease of nutrient feeding. I have adequate aeration in each bucket. My water levels are fine, pump is working fine, and bubblers are working great. My question:

When adding nutrients, how do I evenly distribute so that one of my buckets doesn't get a temporary shock? For example: I have to add enough pH down for a 35 gallon system. If I add the proper dose all to my controller bucket, it immediately shoots down to a pH of 2 or 3 before gradually adjusting to the correct pH as the system recirculates. Same issue arises with nute feedings. Will a quick nutrient/pH spike (talking under a half hour) be detrimental to my plants? If so, how do I properly dose?

Thanks for any suggestions. I appreciate it.

I have never noticed any ill effects from the spike you describe in my RDWC system. Mine circulates a little quicker so its only around 10 minutes to fully stabilize on mine, but I still can't see it causing any problems for you. I mix my pH up/down in at least a half gallon of water though, so I don't see huge drops or spikes like you do. I would advise you mix them like that anyways if you don't already to prevent precipitation - same with nutes.

Sureshot2 said:

I have never noticed any ill effects from the spike you describe in my RDWC system. Mine circulates a little quicker so its only around 10 minutes to fully stabilize on mine, but I still can't see it causing any problems for you. I mix my pH up/down in at least a half gallon of water though, so I don't see huge drops or spikes like you do. I would advise you mix them like that anyways if you don't already to prevent precipitation - same with nutes.

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Thanks for the reply! I'll do that. I had read previously not to mix nutes outside of res. Any truth to that?

lbristol said:

Thanks for the reply! I'll do that. I had read previously not to mix nutes outside of res. Any truth to that?

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You can mix nutes in plain water outside of the res. IMO, its much safer to mix them with a gallon or so of water outside instead of putting straight up nutes in the res when adjusting, since you could cause precipitation with certain nutes (especially silicas for example). The key thing is not mixing two separate nutes together in concentrated form without water such as an A and B on a two part mix.

The Best and safest way is to have a large water butt or drum to mix your nutes in and ph it before you put it in the system, Plants do not like massive changes in ph, if the water butt or water drum is not an option i would do as above and pre mix it in a few gallons first and slowly add it, that way you know your adding a solution that is already the ph correct.

My system has a 250l res which i can send all my nutes back to while i adjust things or add more nutes, makes lif really easy imo.

Happy Growing