Indoor Auto Jack DWC.

[SirTokesAlot]

Hi Guys,
This is my first horticulture adventure and its a blast so far. posted a recent thread in the introductions forum but I am now here looking for some advice on the DWC issues seem to be experiencing. Hopefully the pros/experienced can shed some light on this one.
The strain is RQS auto jack, using bottled mineral water with house and garden hydro a&b. Dutch pro additives with some plant magic mag/cal and evolution foliar spray once a week. This is running under a 250W HPS air cooled light and 300W LED combo with 4" sileo and ram filter fan combo. Water temps are usually about 82f and water bottles don't seem to get it below 73f. The roots could look better with patches of brown etc. PH is at 5.8 ranging to 6.2 at times. Ppm and EC are unknown, a meter will be bought soon just have the old ph pen for now. Kind of short on pennies

here are some pictures, feel free to share your thoughts / experiences and comments, currently not sure whats going on and believe this to be early root rot issues or maybe a deficiency...
Cheers,
Tokes.

 

[SirTokesAlot]

Morning all,

another night passes and little jack is looking worse than 12 hours ago, poor bugger really doesn't look good now.
Last night i changed out the res with a fresh nute / PHd bottled water (5.8) mix and made sure to include some magne/cal in fear of a calcium deficiency.At that time water temps were 68f but this morning its sitting at 80f. ....really hope someone knows my issue and has a solution, atm im watching auto jack slowly wilt away

on the other hand .the sour diesel (back left/ 4wks) and royal dwarf (front left/3wks) soil pots are looking pretty healthy
Cheers,
Tokes

 

[DWCocha]

give a run down on the nutes - ppm - ph ect & may be able to advise on the DWC bud ?

When you test ppm ,is it going up ?

 

[SirTokesAlot]

morning mate, not sure on the ppm atm... going to pick up a blue lab meter shortly only have the ph pen for now. bloody expensive things, guy down the local wanted 180 for the multi meter.

Nutes used are :

House and Garden A + B
Dutch Pro Multi
Dutch Pro Take root
Dutch pro keep it clean
Plant Magic Magne Cal
Liquid Silicone (ph up)

Not used yet:
dutch pro explode,
the canna rhizotonic and cannazym

PH is sitting at 5.9

 

[DWCocha]

edit ...read back & see you have no meters ..that makes things a bit more difficult .Looks like calcium deff from PH drifting too high ,keep it at or below 5.9 for the next few weeks before bloom if you can .

The main problem I can see is your res temps ,82f is insane high .The res cannot retain as much dissolved oxygen & the plants are starved of 02 ...no matter how good your airpump is.

Dissolved oxygen levels in tap water are typically between 5-7 parts per million (PPM) at room temperature. Temperature has a powerful effect on how much oxygen can be held by water molecules. The warmer the water is, the less gas it is able to hold. Fully oxygenated water at 68° Fahrenheit will hold about 9 PPM of DO, while the same water at 86° Fahrenheit only holds about 7.5 PPM (over 15% less DO). It should come as no surprise then that the ideal temperature for maximizing root growth in hydroponic systems is 68° Fahrenheit, the temperature at which water naturally holds the 8-9 PPM of DO, which is the very amount of DO necessary to support vigorous plant growth in most crops. Water holds both dissolved solids like fertilizer as well as dissolved gases like CO2 & O2. The higher the PPM (dissolved solids), the less gases water can hold, so be aware that over fertilizing often occurs in conjunction with oxygen deprivation.

 

[DWCocha]

morning mate, not sure on the ppm atm... going to pick up a blue lab meter shortly only have the ph pen for now. bloody expensive things, guy down the local wanted 180 for the multi meter.

Nutes used are :

House and Garden A + B
Dutch Pro Multi
Dutch Pro Take root
Dutch pro keep it clean
Plant Magic Magne Cal
Liquid Silicone (ph up)

Not used yet:
dutch pro explode,
the canna rhizotonic and cannazym

PH is sitting at 5.9

cool . Next res maybe up your calmagic by a couple ml & deffo add some rhizotonic .I wouldn't worry about ppm to much now as there's no tip burn ,so your not overfeeding .Have you thought about just running the LED for a while as that 250 is bound to be the main source of the heat .

If your PH is going up a lot then reset more often if you can & maybe calibrate the meter ? it's only got to be a bit out & your over 6.0 PH in veg ...that will cause the calcium deff as it's locked out after 5.9

good luck

 

[Waximus]

I'm with DWCocha, Bro.
The rez temps are WAY too high. 74 deg is as high as it should get, or both the risk of root rot as well as pH and oxygen problems will be likely.
Do you have any white plastic that you could wrap the rez bins with? The light color will reflect light from the darker rez containers, and lower the mean temp in those bins. It may only be a few degrees, but if you're using ice bottles to cool, then it may get you low enough.
Also, Yes, you need a PPM meter. Once you have that, it'll be much easier to see whats happening in the soup

 

[SirTokesAlot]

Thanks for the reply mate, its appreciated.
Going on that info some fundamental flaws in my setup are
1) Water temps, ...without being able to purchase a water chiller atm (200+ on ebay) the frozen water bottle wont get it down below high 70's what else would do the trick?
2) Oxygen levels in the water, if the water temperature directly affects the amount of dissolved oxygen does this mean the higher the temp the faster DO levels decrease? Meaning I should change the water out more frequent? also heard peroxide at high temps can help, should i look into the voodoo juice or H2O2 for instance?

And if anyone has a good nute mix / schedule for the ones listed above pls do share, atm im using dutch pro hydro feed schedule with 1/4 the strength mixes.

Cheers all

 

[SirTokesAlot]

Nice one Waximus, ill get on that today. May use spare mylar to bounce the light away.
Thanks for the tip.

 

[Waximus]

On the water temp, wrapping the bins with white/reflective material will help.. Also, replacing the plastic rez bins with insulated coolers would be great! The insulation in the cooler(s) can cut the temp by 10 degrees or more.
As for the DO issue, I think you'd be changing the rez every couple hours with those higher temps. At higher temps, the water simply can't "hold" the oxygen. The DO issue will improve dramatically once you get the rez temps down to a workable level.