pH.... 5.2, or 5.8?

So I've read numerous threads today old and new, having to do with pH. Quite a few "pro's" were posting in them debating, I am looking for some definitive answers/results/opinions.

There are those pH charts posted, the 80's colored neon chart showing 5.8 as optimal that everyone now says is misleading and incorrect, and the black and white chart showing that 5.2 would be optimal.

I have to say, with almost everyone I see on here running 5.6-6.2 without any problems, why would the 5.2 chart be correct?

Does anyone actually run 5.2 successfully and notice an improvement over 5.8?

Thanks for your input.

I let my pH drift. I set it to 5.6/5.7 and it'll drift a few points before I adjust it. Allowing this drift has given me healthier plants.

5.0...

I followed a chart that suggests that lower ph is perhaps better in dWC hydro than the more common charts suggest. The most common charts are for soil. I actually have no idea how accurate this chart is, or for that matter how the more standard nutrient availability charts are made.

I'm just finishing up a grow and mostly kept my ph between 4.5 and 5.2 or so, and things worked out just fine. I did burn the leaf tips with too high a ppms in mid flower, but that wasnt a problem related to ph.

you might find this interesting.

**Added by: MisterIto**Last edited by: 10k**Viewed: 588 times
**Rated by 43 users: 8.77/10
I follow and highly recommend the following parameters for hydroponic nutrient solutions for aeroponic, “bubblers”, drip, ebb and flow, NFT, passive, rockwool and wick systems.

PH 5.1-5.9 (5.2 optimal)
TDS 500-1000ppm, EC .75-1.5
Temperature 68-78f, 20-25c (75f, 24c optimal)

The pH of the nutrient solution is a major determinant of nutrient uptake by the plant. If the pH wanders outside the optimum range of between pH 5.1 and pH 5.9, then nutritional deficiency and/or toxicity problems can occur. For hydroponic nutrient solutions used with inert media, keep the pH at 5.2 for optimal elemental uptake. It is at this point that roots most readily assimilate nutrients. These pH and TDS/EC recommendations may seem low relative to the normally suggested range, but are based upon information garnered from "Hydroponic Nutrients" by M. Edward Muckle and Practical Hydroponics and Greenhouses. They both document the low pH resulting in increased nutrient uptake and my experience has shown discernible health and yield improvements at a ph of 5.2 over higher levels.

On page 100, Hydroponic Nutrients displays both the assimilation chart for organic soil applications and another for inert medium hydroponics, which depicts the vastly different scenarios. The widely accepted soil based chart is frequently misapplied to water culture applications. His research and that done by others, documented in Practical Hydroponics and Greenhouses, indicate that iron and phosphorous precipitate in nutrient solutions at pH levels above 6. Stay below a pH of 6 by all means to avoid this problem and benefit.

The nutrient assimilation rate is further enhanced by the reduction in solution TDS/EC, which reduces osmotic pressure and allows the roots to draw the nutrients "easier". Young, established seedlings or rooted cuttings are started at 500-600ppm. The TDS is increased to 800-900ppm during peak vegetative growth. During the transition from early to heavy flowering, TDS is further raised to 1000-1100ppm. It is then reduced to 400-500ppm during the final 2 weeks of flushing. The plants demonstrate their preference for a lower TDS/EC when running a lower pH by clearly sustaining higher growth rates.

The optimum temperature for hydroponic solutions to be is 24c/75f. At this point, most elements are assimilated highest and atmospheric oxygen is most readily dissolved. Although increases in temperature increase the rate of photosynthesis, avoid exceeding the maximum listed of 25c/78f. Elevated temperatures make some elements more available, but reduce the solution's dissolved oxygen capacity, increasing root disease likelihood.
**Last modified: 05:15 - Nov 14, 2000
*
Quicklink:**http://overgrow.com/growfaq/73
GrowFAQ © 2000-2004 Overgrow
faq:73 "What ranges should I maintain for my hydroponic nutrients pH, TDS/EC and temperature?"

i'm editing this to say that mr ito's ppm values are for .7 meters, if you are using a .5 meter it would come out to 714 ppm, but his ec comes out to 750 ppm.

When I ran the DWCs I kept ph at 5.2 without issues. There was a paper written by a professor at UC Davis in regarding ph in hydro that I read back then which convinced me to lower the ph.

Ph will fall naturally in recycle system. If you run to waste then your ph will stay more consistent. Remmber to flush every 2-3weeks. I use recirc system and set to 6.0. I ph up to 6.0 every few days. They love it.

Honestly, our advice means little. Try different pH values to see what works best for your plants.

delta9nxs said:

you might find this interesting.

**Added by: MisterIto**Last edited by: 10k**Viewed: 588 times
**Rated by 43 users: 8.77/10
I follow and highly recommend the following parameters for hydroponic nutrient solutions for aeroponic, “bubblers”, drip, ebb and flow, NFT, passive, rockwool and wick systems.

PH 5.1-5.9 (5.2 optimal)
TDS 500-1000ppm, EC .75-1.5
Temperature 68-78f, 20-25c (75f, 24c optimal)

The pH of the nutrient solution is a major determinant of nutrient uptake by the plant. If the pH wanders outside the optimum range of between pH 5.1 and pH 5.9, then nutritional deficiency and/or toxicity problems can occur. For hydroponic nutrient solutions used with inert media, keep the pH at 5.2 for optimal elemental uptake. It is at this point that roots most readily assimilate nutrients. These pH and TDS/EC recommendations may seem low relative to the normally suggested range, but are based upon information garnered from "Hydroponic Nutrients" by M. Edward Muckle and Practical Hydroponics and Greenhouses. They both document the low pH resulting in increased nutrient uptake and my experience has shown discernible health and yield improvements at a ph of 5.2 over higher levels.

On page 100, Hydroponic Nutrients displays both the assimilation chart for organic soil applications and another for inert medium hydroponics, which depicts the vastly different scenarios. The widely accepted soil based chart is frequently misapplied to water culture applications. His research and that done by others, documented in Practical Hydroponics and Greenhouses, indicate that iron and phosphorous precipitate in nutrient solutions at pH levels above 6. Stay below a pH of 6 by all means to avoid this problem and benefit.

The nutrient assimilation rate is further enhanced by the reduction in solution TDS/EC, which reduces osmotic pressure and allows the roots to draw the nutrients "easier". Young, established seedlings or rooted cuttings are started at 500-600ppm. The TDS is increased to 800-900ppm during peak vegetative growth. During the transition from early to heavy flowering, TDS is further raised to 1000-1100ppm. It is then reduced to 400-500ppm during the final 2 weeks of flushing. The plants demonstrate their preference for a lower TDS/EC when running a lower pH by clearly sustaining higher growth rates.

The optimum temperature for hydroponic solutions to be is 24c/75f. At this point, most elements are assimilated highest and atmospheric oxygen is most readily dissolved. Although increases in temperature increase the rate of photosynthesis, avoid exceeding the maximum listed of 25c/78f. Elevated temperatures make some elements more available, but reduce the solution's dissolved oxygen capacity, increasing root disease likelihood.
**Last modified: 05:15 - Nov 14, 2000
*
Quicklink:**http://overgrow.com/growfaq/73
GrowFAQ © 2000-2004 Overgrow
faq:73 "What ranges should I maintain for my hydroponic nutrients pH, TDS/EC and temperature?"

i'm editing this to say that mr ito's ppm values are for .7 meters, if you are using a .5 meter it would come out to 714 ppm, but his ec comes out to 750 ppm.

Click to expand...

This is just what I needed! Thanks

I run at a pH of 6 and an e.c. of 1 through most of the life cycle and I don't see any deficiencies. That's the pH that I get when I mix my water and nutrient solution. I don't have the time or inclination to wade through academic papers on hydroponics, I rely on the nutrients manufacturers to do that, as they have the expertise, time, resources and experience to get it right.

tokinafaty420 said:

I let my pH drift.

Click to expand...

Drift is best in my opinion. set low point let it rise up over a week or so.

Grimr3efer said:

Ph will fall naturally in recycle system.

Click to expand...

with my GH nutes the pH rises as the food is eaten by the plants.

I switch PH in Veg & Bloom (DWC), in Veg i find 5.3-5.6 usually the best overall & for me produced better growth all round, rather than Keeping a constant low PH like 5.2, for me its the absolute lowest i ever go. then in bloom i find 5.6-5.8max, sometimes strains do better at different levels again, but never anywhere near 6.0. Same for EC, ive found DWC grown plants prefer a much lower strength EC as apposed to other growing styles like NFT for example. Getting to know what your plant wants & does best at is the overall aim, get to know the strain!.

my plants like it best when the pH looks orange

Japanfreakier said:

with my GH nutes the pH rises as the food is eaten by the plants.

Click to expand...

Thats because you're under feeding. Your plants want more food than you're giving them so they drink food at a faster rate than water. I use GH also and my pH falls as the plants eat but, that's because I over feed for just this reason.

Personally, I've always kept pH above 5.5 but, 5.2 is easy enough to try.

Wow, that's a huge assumption to say I underfeed my plants. I give them the recipe on the back of the bottles, comes out about 1200 ppm.

Even with nutrient addbacks my pH would rise over the course of 2 weeks, it's a slow rise and I never adjust down.

Lorenzo said:

my plants like it best when the pH looks orange

Click to expand...

hahaha

El Toker said:

I run at a pH of 6 and an e.c. of 1 through most of the life cycle and I don't see any deficiencies. That's the pH that I get when I mix my water and nutrient solution. I don't have the time or inclination to wade through academic papers on hydroponics, I rely on the nutrients manufacturers to do that, as they have the expertise, time, resources and experience to get it right.

Click to expand...

Indeed good complete nutrients are designed to bring pH to within a decent range and include pH buffers to stabalize it as well. I know using lucas with my home water, 1100ppm@.7 will make pH 5.8 solution every time. Which is convenient because I tend to be feeding at 1100 for the majority of the bloom cycle.

Japanfreakier said:

Drift is best in my opinion. set low point let it rise up over a week or so.

Click to expand...

+1

Japanfreakier said:

with my GH nutes the pH rises as the food is eaten by the plants.

Click to expand...

Whether your pH rises or falls depends on the rate the plant is consuming nutrients. Simply put, you can pretty much assign a number to the amount of nutrients a plant eats at any given point in its life cycle. Fill your bucket (or res) with a nutrient solution of a known strength, say mix it to 800ppm@.7 let the plant grow in there for a few days or whatever till the water level has dropped because the plant has been drinking. Now go back and check the ppms in the bucket now. There are 3 possible outcomes obviously:

1) the EC/TDS/PPM have fallen...

You check the ppms, and say they are at 700 now....well that means that the plant is consuming the nutrients at a quicker rate than it is the water. We know this because the concentration of the nutrient solution has decrease i.e. from 800ppms to 700ppms (it is important to understand the difference between concentration and volume, EC/TDS/PPM all measure concentration, not volume)This means that you were underfeeding your plant with 800ppm, so you need to raise it, try 900ppm.

2) the EC/TDS/PPM have risen..

You check the ppms, and now they say 900, this means that you need to lower from the original 800, try 700 now.

3) The EC/TDS/PPM is still the same...

You check em, and it still says 800. This is great. This means that the plant is consuming nutrients and water at the same rate. this is what you want. this is the target strength.

You continue doing this same process throughout the entire grow.

Now to get pH to swing up, you find the target strength and then reduce it by a small amount, say 50ppm, so if our mix was 800ppm we would reduce that to 750ppm and that is what we mwould put in the resevoir. That will cause the strength of your solution to drop at a slow, controlled rate. Maybe over the course of 5-7 days the pH will swing from ~ 5.6 to 6.0 which is usually what i do. The rate of swing depends on the total capacity of your system as a larger volume of solution will swing slower than a smaller one. In my 28 gallon system, with 4 plants, my ph swings from 5.6-6.0 over the course of 10-14 days. Note that doing the opposite, say raising the ppms by 50 will have the opposite effect, causing the pH to slowly drop and EC to slowly rise.

In individual buckets everything is magnified (because of the small total capacity), so during bloom when the plant is drinking large volumes of solution it is especially important to be feeding accurately, so you can ensure the pH never swings out of range and The EC doesn't climb very high. If you are overfeeding by a small amount, in individual buckets, the EC can climb rapidly. Especially deak peak blooming.


The second time you grow a plant in hydro, you should be delivering optimum conditions as you have already "discovered" the plant's feeding requirements.

I know all of that but thanks for sharing.

Let it Drift

Let it Drift

When I'm mixing up a new res I shoot for 5.2-ish. I add ro water daily as necessary to top off the rez and allow the Ph to drift up as high as 6.2. I just keep a close eye on the pH and when the rez hits 6.2-ish I adjust downwards, back to my low target. My plants seem to like this regimen, so I keep doing it this way.

Not to mention the fact that you will go crazy trying to keep the pH at a rock solid level of 5.6, or whatever ur magic number is.