Indoor RDWC Grow - Failure at every turn

JMek420

Member
Caused by underfeeding!
Nah man this wasnt underfeeding problem, it was algae.
Some of my smaller plans have light touches of what I assume is nute burn (Slightly browned tips and some leaf edges)
The plants were hardly drinking at all.
The PPM would drop by ~10-20 over 24 hours and ph would go 5.6-6.8 in the same amount of time.
 

JMek420

Member
I want to keep the nute solution at half strength until they bounce back and I get some good healthy root production.
I feel like full strengthing will just burn the roots and hurt them more after the algae attack.
 

polishpollack

Well-Known Member
I dont know why people keep saying this...lol
My first grow had high temps and was successful.
Now I have an auto chiller, water temps are generally around 64-66. Never higher than 68.
I was referring to warm temps causing bacteria to grow. I forgot about your chiller, my bad, sorry.
 

Tripp2005

Well-Known Member
Use the hberg tea bro you won't regret it saved my dwc for sure u don't even need a chiller I haven't yet anyway I just keep the population of good bennies to bad ones way higher and the bad ones die off eventually
 

JMek420

Member
I've been using citric acid for PH down.
I just read that this can cause algal blooms.
Anyone can confirm or deny this?
Thinking about throwing away my PH down and going for phosphoric acid PH down, for obvious reasons.
 

Airwalker16

Well-Known Member

JMek420

Member
https://jrpeters.wordpress.com/2012/03/13/citric-acid-and-algae-blooms/

I looked at your pics again and I'm wondering if the blue hoses you're using allow light to pass. Maybe they're not as light tight as you think. Also it could be there is something about your water that is bringing microbes in via the water supply.
You're possibly right, it is just your run of the mill cheap anti kink garden hose im using there.
I just placed an order with my supply store for all the parts I need to create a new UC-RDWC, with all black fittings, all black flexi hose, and rubber matting for the top of my sites to prevent light leaks through the rockwool/hydroton.
Should be here by the end of the week.
 

polishpollack

Well-Known Member
you might consider using distilled water or somehow using water that has been sanitized. another issue can be the fert you're using which might feed microbes in water. It's something you need to research.
 

JMek420

Member
Ill be honest, since I ran the clean water for 24 hours, cleaned the roots and added my GreatWhite tea into a fresh batch of weak nutes, things are looking not bad....so far.

PPM is declining slowly at rate of ~ 40 ppm / per day.
PH is rising slowly, only went from 5.8-6.3 in 36 hours
Im going to guess and say ~ 2 litres of water has been consumed from the system.

Water is mostly clear with only faint smell of damp rainforest (From the tea I guess, definitely not a bad smell).

I just PH'd the solution again down to 5.5 using hydrochloric acid (pool PH down) and added a bit more nutes to bump the solution up to 450 PPM, and added another cup of my tea.

Plants look perky. No drooping or further discoloration yet.

Might be crisis averted?
 

polishpollack

Well-Known Member
"All strong mineral acids are extremely dangerous. Those most commonly met for hydroponic use are phosphoric and nitric. Hydrochloric acid (muriatic, or ‘pool acid) is readily available, but should never be used in hydroponics because it adds unwanted chloride ions."

http://www.hydroponics.com.au/what-acid-should-i-use-for-ph-control/

phosphoric acid probably works like a fert, but might be the safest. it is possible to use new battery acid which is sulphuric acid. Use the ppm level to create your pH, meaning that if the ppm is dropping and the pH is rising, this most likely means that the plants are eating well. I'd say raise the ppm which will cause pH to drop and maybe don't worry so much about controlling pH with additional acids, and see how that works in the plant grow.
 

JMek420

Member
"All strong mineral acids are extremely dangerous. Those most commonly met for hydroponic use are phosphoric and nitric. Hydrochloric acid (muriatic, or ‘pool acid) is readily available, but should never be used in hydroponics because it adds unwanted chloride ions."

http://www.hydroponics.com.au/what-acid-should-i-use-for-ph-control/

phosphoric acid probably works like a fert, but might be the safest. it is possible to use new battery acid which is sulphuric acid. Use the ppm level to create your pH, meaning that if the ppm is dropping and the pH is rising, this most likely means that the plants are eating well. I'd say raise the ppm which will cause pH to drop and maybe don't worry so much about controlling pH with additional acids, and see how that works in the plant grow.
I just read a few things about phosphoric acid being good for hydroponics. Yeah I read the same thing about hydrochlorics and not to use them, I didnt want to use citric again but incase it fed the algae up, so I figure one little dose wouldn't do much harm until I get my new bottle of PH down.


You mixed the nutrients in a separate gallon or so of water THEN added it to your res right?
Hey man, I flicked off the recirc pump and added my A-part nute to my control rez directly, stirred vigorously and then added my part-B.
Then I added a small amount of HCl to about a litre of RO water, and then slowly added that until my PH reached 5.5. Then I flicked my pump back on to let it recirculate and mix in with the rest of the system.
Is this bad form?
 

pinner420

Well-Known Member
Correct... Bad form.. Two parts are separated for the exact ratios in witch they are intented to be blended on a blank slate. If it where a 1 part like Ionic then I'd say let it roll.
 

polishpollack

Well-Known Member
pinner, somehow that doesn't sound right. don't you mix A and B together, then pH down? A in water first, then B, then pH, or am I mistaken?
 
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