pH behavior

[dank_]

I change the rez and the pH usually stays around 5.6pH or swings from 5.5-6.3. The ppms always go down, the rez is untouched until I change again. Towards the end of the week, the rez is no longer in equilibrium and the pH slowly start rising (I maintain 5.5-6.5pH). THEN as early as day 5 of 7, the pH will take a nose dive around 4.6! What is this indicative of?At this time the ppms are usually ~<200. I keep adjusting UP until I change the rez next.

I like the way I feed; I don't top off the rez, I feed once and only adjust the pH throughout the week.

When the pH drops, I'm considering the rez at that time. What do you think?

 

[1st.artuning]

what are the ppm during this cycle? What stage are you in? Need more info... what type of system? do you have a water chiller?
Describe your system and environment to get better help....

 

[stickyicky]

Root rot can cause ph fluctuation.

I have the opposite problem. My ph is shooting up. Within 2 days of changing rez. it goes from 5.5 to 6.2 overnight. It does this for about 4 days and then stabilizes. I'm using ro too!

 

[dank_]

Aeroflo, 30 plants in 5' x 8' under 2Kw.

Feeding Connoisseur, CalMag, VooDoo, Piranha, Tarantula, CarboLoad. During flower I max out ppms around 650-800 around week 6.

I'm in early week 4 flowering. But the behavior is evident in veg also. It's all in the last few days of the week.

~30gal rez, 65-57F, 62-60F @night. No problems with the roots.

Room 71-77F, 40-70% RH

pH is well monitored.

http://i94.invalid.com/albums/l100/realbluntz/thed/DSC09113.jpg


In those latter days of the week when the pH drops, I feel the need to take action. Using pH UP is not a solution because it is needed every few hours.

 

[Seamaiden]

They sure do look happy for all the fits you're having over the pH shifting. Seriously.

 

[stickyicky]

They sure do look happy for all the fits you're having over the pH shifting. Seriously.

I second that. They look great. Ride out the storm I guess.

 

[mastacheeser]

just do a rez change every 5 days
unless ur in some sort of massive uc system its really only 2 or 3 more rez fills per cycles
adding less water and topping off will either solve your problem or make it twice as bad

 

[mastacheeser]

haha just noticed ur running a aeroflo. your going to have probs if your not sterile. i used to have probs and now i change every 5 days. some weeks i run sterile, some weeks i run gw. when ever the gw is in there my ph bounces so it leads me to beleive the extreme aeriation of the aeroflo causes bacteria to over-multiply and eventually lead to bacetia fallout. im running two of these systems check out my cheesin room

 

[cephalopod]

Hey Mastacheeser, sorry if I'm missing it but, whats gw? I'm in aero and have been filling the tubes and res to the brim in between crops add bleach to 150-200ppm run for a few days and rinse with florakleen. Between changes half strength florakleen. I use bennies all the way through compost tea and floralicious+.

 

[mastacheeser]

great white from plant success
just a bene bacteria and some other b.s.

the benes are about half as good in these systems because they actually have to attach them selves to the roots to work good. some others that commented earlier are alot more qualified to answer questions about beneificals so im going to leave it at that.

from personal experience im alot happier going the sterile route in aero. no more compost tea runs to the hydro store either

also grab some silicone instead of ph up, dyna gro protect is what i use

p.s. 24 hours after a rez change my ph will go from 5.9 to 5.4, almost every time. it stabalizes after that. when i was running benes, it was a twice a day thing to p.h., would go from 5.9 to 5.4 twice per day. sea kelp extracts will also treat you very good in these systems

 

[smokestack23]

from personal experience im alot happier going the sterile route i

Same!!

 

[dank_]

Seems the pH ascended to new lows. First it was 4.3, 4.6, 5, 5.3 and now 5.5.

No storm here, just trying to understand more. I thought the drop had to do with the nute strength - I have determined that to be untrue. I really thought when I stained everything with Tarantula, that was the cause. Nope, the pH was dropping in veg, also.

I'm OK with calling this behavior normal, I just want to understand it more! Why the hell can't I find a botany class anywhere??

The plants looks fantastic. The burns you see on the leaves are from too much GreenCure.

 

[Jalisco Kid]

You might want to look at what kind and how much nitrigen is in your formula. Drops in certain kinds of N will lower pH and viceversa JK

 

[Gartner]

Mainly ph level is maintained by the mineral content of the soil, and the water, use mineral water, if its affordable so that the ph level can be brought up to 7.0
also i am using organic fertilizers... which is also helpful to maintain the ph level...

 

[DMTx6]

Root rot can cause ph fluctuation.

I have the opposite problem. My ph is shooting up. Within 2 days of changing rez. it goes from 5.5 to 6.2 overnight. It does this for about 4 days and then stabilizes. I'm using ro too!

I have the same problems. Is it usual for the plant to raise the ph? I start my week at 5.3 and the next day it jumps to 6.4. Should i start my rez out at say 4.3 so that it evens out at somewhere around 5.3-5.5. Thanks

 

[dank_]

[solved]

I can't explain the rush I got after reading this (a lot of the rush had to do with the anxiety from this very potent AK47)

Water Quality - thanks, greenblood

I'd like to test the alkalinity of my water, but I don't think I have to now.

Jalico, you're right on the money! I think I may change my nutes.

Effects of Low Alkalinity

Not everybody in North America has irrigation water with high alkalinity. The primary problem associated with low alkalinity water is a tendency for media pH to drop over time. Growers often run into low pH problems when low water alkalinity is combined with a fertilizer high in ammoniacal nitrogen. Fertilizers high in ammoniacal nitrogen are acidic, and without any alkalinity in the water to balance the reaction (resist lowering of pH), acidic fertilizers will tend to drive the media pH down over time.

Fertilizers that are high in nitrate nitrogen often do not cause the media pH to increase when combined with low-alkalinity water. In fact, it is often recommended that growers with low alkalinity water use fertilizers high in nitrate nitrogen simply to maintain a stable media pH. When low media pH does occur in conjunction with a low-alkalinity water source, raising media pH with high-nitrate fertilizers may be difficult or impossible. Growers with low alkalinity should stock potassium bicarbonate or liquid lime, which raise media pH.

 

[desertsquirrel]

normal ph swings 5.5-62 are what your experiencing in the first half of the week and then it starts to dip lower and lower?

I run the same ph swing (well 5.2-6.2) and the only time i see it charge lower and lower is a result of running bennies in the system too long. If you let them run unattended they will seriously drive your ph down.

I use that to my advantage and dont add them till late in the rezz change. that way i dont need to use a chemical ph down. I only run the bennies for about 4-5 days at the end of the 2 week rezz cycle.

 

[desertsquirrel]

also advanced uses urea in their profile (ammoniacal nitrogen) so id look into what jalisco said as well...

 

[PhatNuggz]

organics and hydro is tricky. I switched to DM nutes for my last and foreseeable future grows as the results were excellent and my rez pH issues went away. Also I do not recirc nutes

hth

 

[dank_]

[solved for the final time]

I have FINALLY concluded that the reason my pH drops is because of my beneficial bacteria.

Rep to whomever suggested that in the beginning