Battery acid pH levels in coco

I'm at a loss as to when I water with pH 5.8 water/nutrients I get a run-off of pH 4-4.3. How can I rectify the problem? Have only grown with coco once before and had the very same problem - the last time I tried to elevate the pH by watering with high pH water(pH 10 plus). This helped a little but as the coco buffers like mad it was not a perfect solution to the problem. Will flushing with copious amounts of tap water re-stabilise the pH? Due to the extremely low pH I'm now seeing the signs of nutrient lock-out,especially mg/cal deficiency. I'm only a few days into flowering so hopefully it's not too late to sort the problem out! I'd be grateful for any help with this problem!

Growing in coco you don't need to worry about the runoff. Mix your nutes, ph/ppm your batch, feed as needed..

I never check the runoff PH in soil or hydro. I'm in coco this grow, flush it with a gallon or 2 of 5.8-6 water then feed it as normal with 5.8 again. Putting in a solution with a PH of 10 is about the worst thing to try. What goes in isn't what comes out. I use tap water so I never have cal/mg issues. I PH my water immediately before I use it, if you mix a batch and let it sit days waiting to be used it will start to fluctuate and I prefer to only PH once.

Did you do any flushing during veg to clean out the salts? For example, my plants each currently use about 6 cups of water each day with little to no runoff. Every two weeks or so I'll run a full gallon of plain 5.8 water in each plant, there is some runoff. Then I immediately follow with their regular feed mix of 6 cups at 5.8 as well which in turn forces out a lot more of the previous gallon.

Really low ph runoff can be a sign of overfeeding..like youre putting in more than what the plant is using so it builds up. I would just water with a weak solution for a while (1/4 strength..maybe 200-300 ppm) at normal ph range of 5.8 - 6.2 for coco..dont try and overcompensate by watering with some way off ph

Thanks for your good advice concerning my coco run-off problem. I've usually grown using NFT and as I'm new to coco I was unaware of some of the finer points concerning it's use.I'll now continue with confidence knowing that run-off pH is not as big a problem as I imagined. I'll address the Cal/mag problem by adding some low doses of individual calcium and magnesium (Canna) nutrients to the Canna Coco A&B until the leaves green up more. Once again many thanks.

Cheers, that sounds like good advice. I was also pleased to hear that I don't need to water to run-off all the time. In answer to your question - yes I did flush thru the pots (15 litre) after veging but as I was concerned with the low pH I just used plain tap water (pH 7.5) instead of the usual pH 5.8. I gave them a really good rinse with 15-30 litres (a little excesive perhaps but at the time I was trying to up the run-off pH!). I too just use tap water that I've left standing for 24hrs (to remove any chlorine) but I still appear to have some early signs of cal/mag deficiency. Would it be beneficial to treat this with a foliar spray with some cal/mag just after lights out or would it be more beneficial to add a low dose to the regular nutrients?

Thanks again for the advice and I'll try not to stress too much about run-off pH

Thanks for your prompt reply and I found your comments about overfeeding could indeed be the cause off the low pH run-off. I also take your point about the bad idea of trying to compensate with a high pH watering. When I tried this ill thought out method during my first coco grow it had very little effect anyway as coco appears to be an extremely good buffering agent..... probably only just scared the living daylights out of the roots!
I would be interested on your thoughts concerning treating cal/mag deficiency. Once again many thanks for your advice.

coco has a high CEC and as you stated buffers a lot. Many growers rinse and pretreat coco with Calcium, Magnesium first. I rinset with water soak with a solution of epsom salts and Calcium Hydroxide and rinse again. CalMag also works but costs more. Others don't do a pretreat and rely on having calmag in their watering solution. Even though I use tap water I always have a little cal mag in my nute solutions for coco.

Get some calmag and use it in every watering

did you soak and flush the coco before using it? Because it grows near the ocean, there are a lot of salts locked in the coco. It's usually washed already but just to be sure, i soak and buffer it to 5.8 or so over 3 days, dumping the water each day. its a pain in the ass though, but i don't have problems. I believe the salts are what changes the pH

CoCo retains salts more than other growing mediums.