HYDRO "feed as EC requires" but what about ph?

[treetop]

I'm running Fox Farm liquid and soluble nutes in flood and drain. I use RO+DI water, I always add Cal Mag to fresh and replenished water. When they say "feed as EC requires" it means add more N-P-K fertilizer after replenishing. It just seems vague. GH Cal Mag has high ppm, vs liquid or soluble nutes. It would be easy to overfeed. Also these additional nutes really lower the ph, so I have to keep raising it. Seems wasteful, sub optimal. What am I missing here? I suppose I could use a stronger ph base. I know I don't need to use as much fertilizer as they say. I'll probably switch to GH Flora when these are used up. I know everyone has their favorite.

 

[gbauto]

Hi, treetop.
I can't make out in the picture what you're using as the medium for the f/d.
I'd say that using hydroton wouldn't have an impact on the ph, but I have read of people fight ph issues using f/d with coco or peat.
I target 5.8 in hydro and 6.1 in coco.
I've used the GH Flora trio as well as Megacrop. Both performed well, I preferred using a dry mix over the bottles but I had issues with the megacrop turning to soup from the humidity.
I switched to Jacks 3-2-1 a few years ago and it's just what I was looking for.
Simple, 3-part dry mix that's cost-effective and gives you some adjustability on npk ratios.

 

[YYCannabis]

Hi, treetop.
In hydro, your water pH will always fluctuate. For most people, the pH will climb after doing a fresh nute change or topping-off water levels. Usually it will stabilize after you adjust it for a second time, but you still need to check pH every day and adjust as needed. During veg, it’s good to let your pH drift up and down in the range of 5.5 to 6.5 so that different nutrients can be absorbed by the roots. Since some nutrients are only taken up by the roots at different ends of the spectrum, letting the pH drift will help touch all the right levels.
Have a look at the chart below...you will note that Manganese is only taken up at 5.6 or lower. Where as calcium is at 6.2 and higher. If you keep the pH locked-in at a specific number for too long you could create nutrient deficiency issues.

When the bottle says “feed as EC requires” it’s because the plant will deplete nutes as it grows. Monitoring the EC, pH, and water res levels daily can tell you if your mix is too weak or too strong. (See pic 2)

 

[treetop]

Thanks for the reply! It is hydroton, hard to tell from the pic. I will keep this advice in mind.

 

[treetop]

Thanks @YY! I noticed this pattern. I get it. I have some vegging dwc buckets that are thriving, even with the ph drifting up to 7.5 at times. It is hard to access to nutrient and ph it. And yet the leaves are immaculate, the roots are ultra healthy.

Vs the flowering flood table, above, which is getting ph buffered, replenished and ec fed regularly. That is why I think the soluble replenish nutes are too acidic. Also wondering if the RO+DI water is too empty. And consequently is unstable. Like maybe the DI is taking out too much, thus requiring more cal mag and ph up. Finally that stronger ph buffer may stabilize the current regimen.

 

[YYCannabis]

RO/DI water is stripped of all the micronutrients. Special attention should be given to make sure they are provided. I use tap water so I’m it sure what other DWC/hydro growers do to replenish the micro nutrients.
It might be worth searching the forums or the main GWE website for info on it.

 

[treetop]

@ YY That makes sense. Thanks for parsing my thoughts. The Fox Farm nutes are loaded with micro nutrients. But I will pay closer attention to the ph. I found articles on GWE talking about nutrient deficiency like mine being often ph dependent. I'm thinking I will use a bit more cal mag as these obviously get depleted first. I will try the stronger buffer. Glad to hear I'm not off in the weeds!