DWC 250w hps grow

[nbuus]

Hi to all fellow growers!

I ran into a problem with my 250w hps DWC grow.

I started off with four LSD clones (medium: hydrotone) and i put each one in a 10 liter (2.6 gallon) container. I use GHE flora series for fertilising. At first i used a mild mixture (3ml gro,3ml micro,3ml bloom on 10 liters of tap water + ph regulator).

The clones were doing excellent! But this sunday i replaced the solution with a stronger mix (15ml gro, 10ml micro, 5ml bloom on 10l of tapwater - I've found this formula here: https://www.icmag.com/ic/showthread.php?t=21119 ). Suddenly the growth of my clones has slowed down and they won't grow! What could be the problem here?


Here is some more info:

Solution water pH: 5.5-6.8
Solution water EC: 1.35
Air temperature: 25°C (77°F)
Solution temperature: 22°C (71.5°F)
Humidity: 55-75%
Solution oxygen: 500cc per gallon
Foliar feed: Yes


I am looking forward to any help or solutions. Thank you!

 

[CannabisFox]

1. use the forum upload next time plz
2. thats a magnesium def
3. ec 1.3 is quite high at this stage imo
4. with hydro you dont want our ph above ~6.1

I suggest to get some cal/mag stuff.... but first check if the def was caused by your high ph

 

[nbuus]

Thank you for your reply!

When i change my solution i start with 5.5 pH. Then it slowly rises to higher level. It is curently 5.9

So could this be a magnesium def anyway?

And also: Could i just use extra GH bloom (it contains 3% Mg) to cure this problem, or do i have to get separate Mg stuff?

Also what EC would you recomend at this stage?

peace

 

[FreezerBoy]

Does look like low Mag or possibly sulfur. Either way, at 1.35 EC in tapwater I can only imagine deficiencies from pH lockout (unless tap is extra low in EC to begin with. What's the tap's EC to begin with?) pH range is 5.5-6.0, some say as low as 5.2.

With GH Flora Series, the green "Grow" bottle is unneeded. MJs preferred NPK proportions cannot be approximated using "Grow". Without "Grow" you can hit these proportions almost exactly. For Veg use Micro and Bloom @ 1:1 (as in 5ml each), for aggressive veg 2:1 (as in 10ml Micro+5ml Bloom). For flowering use Micro and Bloom @ 1:2

If it's a true deficiency. Cal Mag or Epsom salts are good Mag sources.

 

[FreezerBoy]

Oh yeah, Image shack will rat you out in a heartbeat. Store shots here at IC. It's a safety thing.

 

[nbuus]

@FreezerBoy first of all thank you for replying second of all - The EC of my tapwater is 0.34. The default pH value of my tapwater is 6.9

Thank you for telling me floragrow is obsolete. I would've never imagined that
And also thank you both for telling me it's better to upload pics here

I will now try using 1:1: Micro:Bloom. What EC would you recomend?

peace

 

[FreezerBoy]

At .3 it's hard to imagine actual deficiencies exist.

Preferred EC levels are determined by the plants. It's why we measure and chart EC and pH. EC and pH should move in opposite directions (nutes are acid, more nutes=lower pH)

EC up, pH down is too rich. EC down, pH up is too lean. When my tap was 0.5 I fed around 1.0. Now that my tap is too low to measure, I'm feeding closer to 2.0. Why? Still working on that but, my point remains; Only your plants know the proper EC.

You could try the Lucas formula, a "one size fits all" option. Many swear by it. I prefer to tailor to my plants request.

 

[nbuus]

Okay so EC up, pH down - no go
and EC down, pH up is also a no go

So how do you know you are feeding right? If your pH and EC are moving in the same direction?

 

[thinkin]

feeding right, plants are nice and green ( i bet you knew that)

Stable PH and stable EC
a slight drift higher in PH is acceptable

As mentioned by Freezer Boy, your problem looks like nute problem

But a warning about foil, dont put the foil right up to the stem.
Foil will thrash the stem. IT WILL hurt/kill your plant.
I wouldnt use foil on top of your netpot. I switched to paper plates.

First sign of anything remotely related to nute problems, i do a rez change. (go back to last % that didnt have a problem)

Peace GL

 

[nbuus]

Thank you a lot!

peace


EDIT: Now i've found moldy-like dots on my hydrotone.

IS that mold? And what can i do if it is? If i keep my pots uncovered - the light will cause algae growth in the tanks, and if i keep them covered - well obviously they develope mold?

What would you do in my case?

peace

 

[thinkin]

mold or salt

mold or salt

mold or salt?

Looks like hydro salt to me.

If Light is hitting the hydro, PH will quickly drop to 5.1. It will stay/ or keep dropping back to ~5.0 until the light problem is fixed.

As long as hydro level isnt too high relative to top of hydroton, net pots will not need covers. My setup is not conventional but, my hydro level is 1.5-2" below the top of my hydroton. The conventional setup, the whole (small) net pot is out of the hydro by middle of veg.

(check out my grow for an example)

Peace


spread some good karma !

 

[Scrogerman]

...

 

[Scrogerman]

Thats simple salts mate! hydroton always gets it(even in low light), rockwool too!! i like to pick off the worst top few, wash & replace & leach the pots now n then as maintenance! nice macro of it btw! if you cover using vented covers(ie, very low light) you'll still get it, capillary action, its just salt accumilation/evaporation from ya nutes!! direct light just speeds up the process ime! nothing to worry about really, just a bit of maintenance to control.

 

[nbuus]

Thank you all for sharing your wisdom.

I have a new problem though.
It appears there is algae growth on the roots.
But i cant imagine how light could get to the water.
I spray painted the containers with several layers and they do not let through light. For covering pots i now use white 5mm thick plastik and it also does not let light pass through.


Yesterday i changed the solution in the containers.

On 10l of tap water with 0.34 EC i used:
8ml GH Micro
8ml GH Bloom
3ml of HESI ph down


I got a pH of 5,5 and EC of 0.85

Today i measured again. PH has spiked up to 6.1, and EC went down to 0.81

Does this mean i should use more nutrients?

peace

 

[nbuus]

Here are some pics

 

[eddie dash]

Be sure ur temps are 72 or less and I highly recomend zone by dutch master! I had a bad case of root rot and 3ml a gallon in my dwc had them exploding with white roots better than ever in a week. All the stuff that was on my roots was dead in a glob at the bottom of my tub.

 

[eddie dash]

And I had tried EVERYTHING else.....it prevents also at a lower dose. I don't know your res temps but a 3inch cpu fan on 3 inch duct into the lid of my 4 gallon res cooled it 8 degres and kept light out.

 

[Hydro-Soil]

Today i measured again. PH has spiked up to 6.1, and EC went down to 0.81

Does this mean i should use more nutrients?

Yes. Since you have Flora nutes I would highly recommend 0-8-16, no cal-mag or additives at a pH of 5.4 (unless you have a top off float valve and then go 5.2)

When you hit the right ratio of nutes you should see a SLOW pH rise. Don't let it get higher than 6.0... IME plants don't really like that range of pH in dwc/swc.

Stay Safe!

 

[nbuus]

Thank you both!

Yes. Since you have Flora nutes I would highly recommend 0-8-16

Do you mean 0-8-16 as in N-P-K, or grow-bloom-micro?

 

[Hydro-Soil]

0-8-16 as in Grow-Micro-Bloom. Yep