My first functional Ebb & Flood setup

[McGuiver]

I just checked my PH 12 hours later. It is at 5.5 PH. It is holding. Don't know what is causing the wild swing.

Will start checking every 12 hours. I was only checking it every 24 hours.

 

[John1234]

Curious, what are you using for pH adjustment?

 

[McGuiver]

I'm using this to buffer.

http://generalhydroponics.com/site/index.php/products/maintenance/ph_buffers/

 

[McGuiver]

I checked it 12 hours later. PH is 5.5. I added some CalMag+ to the water. PH came up to 6.0

Will check it in the morning to see if it goes anywhere.

 

[McGuiver]

My PH is 6.0 and my TDS PPM is 470. Temp is 72 deg F.

That converts to 0.735 EC.

Is this good? Thanks for the help guys. My first time doing hydro.

 

[queequeg152]

your Ph is fine. but the ec is low however, for a hydro setup at least, and its understandable that you could see Ph swinging.
 
 
so my tap water is like 350 'ppm' idk what the ec is. This is just the conductivity tho. your nutrient solution is basically the same ec as my tap water.
 
here is the thing however
my water analysis reads like 200mg/ of combined carbonates, it takes me like 1ml of 37% hcl to drop  the ph of  one gallon of tap water from 7.4 to 5.5-6.
combined carbonates make up almost all of the TA (total alkalinity) in my tap water, as we have little sulfate magnesium etc, its mostly calcium... a bit of mg.
 
its alot harder to change the ph of my tap water than it is to change the ph of your nutrient solution.
 
total alkalinity is a measure of how hard it is to change the ph of water.
 
carbonates buffer ph basically,
 
you really need to know how much alkalinity your solution has, to really understand what is going on here. 
if you have very low alkalinity, simple changes in water chemistry such as allowing co2 to come out of solution,(letting tap water sit out) or algae blooms will result in measurable changes in ph in short periods of time, also plants uptake of fertilizers will result in changes as well. 
 
it is very difficult to control the ph of a non static low alkalinity solution.
 
when i run tomatos in my fertigation system i run them at 3ec pretty much 100%. peppers are at like 2.5 to 2ec depending on how the runoff comes.
because the ec is so high, and there is so much calcium + carbonates from my tap water + chlorine to kill algea, the ph does not budge at all for the week it takes for the tank to empty,
even if i let algea grow it does not measurably alter then ph more than .5 ( measurement threshold of litmus paper imo)
 
IDK why your ec has to be so low tbh, but if i were you i would at least experiment with raising it with carbonates and or excess calcium in the form of calcium nitrate.
 
otherwise your ph will require frequent alterations as you have noticed.  it this insnt a big deal to you, then dont do anything, but it sounds to me like you are looking for a way to stop these fluctuations?
 
fwiw:
 
you mentioned that you buffered the solution, but it seems like you were referring to an acid as you linked to a Gen hydro ph down product.
most acids are not going to buffer the ph at all, just drop it.

 

[Jeff H]

Man McGuiver, I wish I could help you with your pH swings, but I have seen nothing like that in my flood and drain system.
 
In case you don't know, I have a 2'x2' table and a 9 gallon rez. I'm lazy and only change the solution every couple of weeks. I start with 700 ppm of nutes + 200 ppm of tap water and a pH around 6.5. After 2 weeks, I checked today and had a pH of 6.75 and a PPM of 570. I'll change the solution later this week when I have a chance, but this is very typical of both my flood table and my dutch buckets over the summer. Something in your system is causing the pH swing.
 
I've been doing this for a couple of years and have enough repeatability in my system that I often don't check pH and PPM for a week or more. It is almost always predictable. pH is fairly stable once buffered down and ppm starts at 900 ish and slowly goes down as the plants use the nutes.
 
Do you oxygenate the reservoir?? I do. The water would get stagnant and nasty if  didn't. DOn't know if that makes a difference, but it keeps my water clean and fresh.

Yes, it is only a test. Once I have mastered this one cycle, I will move to peppers. I can sacrifice my Lucky Bamboo without guilt, but killing innocent peppers plants, well... I can't eat my Lucky Bamboo...

 
I hope you have a bigger system planned for peppers. A 3 gallon rez is barely large enough for one plant, maybe two, but that is pushing it.

 

[McGuiver]

I'm using RO water at about 7ppm. I think I need to add more nutrients.

I think the clay on the rocks caused the PH swing. Looks like it stabilized.

I do have an air stone in the res. it is a micro pore. Lots of micro bubbles. Looks like it is boiling.

I will get a bigger setup. This is just for testing, and small pepper plants.

From being in aerospace & manufacturing we always started small and scaled up.

Makes it easier to perfect the process.

 

[McGuiver]

My PH went back up to 7.5, I just dropped it to 6. I also added 16ml of (50%) hydrogen peroxide to 4 gallons of water. I think this will help. I need to change some tubing on my pump today. I will empty my tank then.

 

[Mojorizen]

Those pH swings are crazy.  I wonder what is causing them. Could be the clay on the rocks. Check pH of water in a cup and then put some rocks in it and let it soak overnight and check the pH again. This would confirm that the rocks are at least contributing to the wild pH swings.  Seems possible though.

 

[McGuiver]

I cleaned out my rez today. The Lucky Bamboo are growing roots.

I pre-rinsed the rocks before I put them in here. The water had a clay residue in the bottom of the container.

Here is it flooded with the residue mixed up.

I'm sure the clay caused the PH swing.

Rocks are removed and are soaking to be cleaned in another container.

 

[McGuiver]

Cleaned out everything.





Now the water is clean.

 

[McGuiver]

Here is my setup from a clean start....


15 L RO water @ PH 6.0

5 doses of 4L setting of MSR MIOX Pen.

*****
Pool Test Strip

FAC - 3

Total Chlorine - 5

Alkalinity - 40

Cyanuric Acid - 0

PH - 6.2

TH - 50

PH with pen 7.2
*****

Added 2.5ml PH down...

PH - 4.2 with pen...

*****

Added 4x 5ml of Cal-Mag +

Added 4x 5ml of Pro-Silicate

PH - 8.0 with color solution...

Added 3ml PH down...

PH - 5 with color solution...

PH - 6.1 with pen... Verified with 4.0 cal solution.

*****

Added 4x 5ml of AquaShield...

PH - 5 with color solution...

PH - 6.1 with pen...

TDS - 412ppm

*****
Final with rocks...9L of Rock...

PH - 6.1 with pen

TDS - 425ppm

11 Lucky Bamboo plants

1 - Sweet Basil plant

1 - Mystery Pepper plant

*****
Mystery Pepper roots.

Sweet Basil roots.

Lucky Bamboo roots.

Lucky Bamboo root nubs.

Final setup after cleaning.
15L of RO water, 9L of rock.

 

[Mojorizen]

Looks good. How many clones all together are you trying to get going?

 

[McGuiver]

The 11 Lucky Bamboo are all clones from a mother plant. The Sweet Basil is 7th or 8 generation clone from its mother plant.
The Mystery Pepper is 2nd generation clone from its mother plant.

I'm just trying my luck with this setup. Seems to be working OK. Just getting the hang of it.

 

[John1234]

From reading your pH notes above, I would guess you have a Bluelab pen? Storing in KCL keeps the probe "close" to calibrated, but I can't stand the bloody things, always reading higher than controls.

 

[McGuiver]

From reading your pH notes above, I would guess you have a Bluelab pen? Storing in KCL keeps the probe "close" to calibrated, but I can't stand the bloody things, always reading higher than controls.

Yes it is a Bluelab pen. I do store it in KCL. Even just Calabrated it is 1 PH high, compared to Alcohol drops or litmus paper.

Don't know who to believe. I do trust the Alcohol or paper.

From reading your pH notes above, I would guess you have a Bluelab pen? Storing in KCL keeps the probe "close" to calibrated, but I can't stand the bloody things, always reading higher than controls.

How do you fix the high readings? It has been calibrated many times.

 

[queequeg152]

never heard of alcohol drops tbh. are these the colormetric drops?
 
im a paper guy myself, once the particular blend is established that is.  IE all the raw salts + tap water + 25ml of hcl, then ill just verify with litmus, and every few days thereon.
 
imo plants do not merit such scrutiny, were not running a chemcial reactor i alway say.

 

[John1234]

Yes it is a Bluelab pen. I do store it in KCL. Even just Calabrated it is 1 PH high, compared to Alcohol drops or litmus paper.

Don't know who to believe. I do trust the Alcohol or paper.

How do you fix the high readings? It has been calibrated many times.

 
I've tried speaking with them, but it gets no where. I've rarely had a problem with the Guardian (it uses a better probe), but it is overkill for pretty much everything short of large scale production, and a lot of those guys ditch the meter and just use drops/paper.
 
I haven't gotten around to returning it, and might be outside the warranty period either way Lesson learned.

 

[McGuiver]

never heard of alcohol drops tbh. are these the colormetric drops?
 
im a paper guy myself, once the particular blend is established that is.  IE all the raw salts + tap water + 25ml of hcl, then ill just verify with litmus, and every few days thereon.
 
imo plants do not merit such scrutiny, were not running a chemcial reactor i alway say.

Yes those colorimetric drops are alcohol. I also have litmus paper, and trust them near 100%.

Here is the MSDS.

http://generalhydroponics.com/site/gh/docs/prod_msds/pH_Indicator.pdf