Identification and fixing help please

[Greengrower]

Hi guys! Any help would be appreciated.
Problem: discoloured leaves, I believe to be a calcium deficiency on the first plant (dark devil)
Medium: soil; biobizz light mix with additional perlite
Feed: biobizz grow .5ml/L (stopped now) biobizz bloom 1ml/L
Water is straight from tap, once nutes are mixed the ph ranges between 6.7 and 7 unsure on EC/TDS
Strainark devil auto - 7weeks old.
And critical 2.0 auto x2 7weeks old
Climate: lowest temp 17c, highest 28c
Lowest Rh 40% highest Rh 70%
Light: Mars hydro 600w led
Symptoms appeared about a week ago but have progressively got worse and is infecting more leaves as time goes on. Infected leaves getting worse as time goes by and I feel like it's spreading.
Will post the pictures of each plant as different comments. Dark devil here first
Thanks!

 

[Greengrower]

1st critical

 

[Greengrower]

2nd critical

 

[OregonBlackBear]

When you're growing in a light soil like biobizz light you need to feed more than just a basic grow nute. You're going to need a grow, a bloom, a micro nute, and a cal/mag as a base nute regimen.

Think of biobizz light as a soilless medium. There are no nutes in it, micro or macro. You have to supply everything.

 

[OregonBlackBear]

Go to the Biobizz website and look up their recommended feeding schedule for light mix, that should help.

 

[Marshydro]

Light: Mars hydro 600w led

Hey @Greengrower, thanks for your support to Mars Hydro, do you use the TS600 light now, 100w?

 

[Marshydro]

Problem: discoloured leaves, I believe to be a calcium deficiency on the first plant (dark devil)

I think it's the nutrients issues. Help him @Mañ'O'Green , please

 

[KnothingfromNobody]

The damage on the Dark Devil looks like late stage potassium deficiency. The Critical looks like early stage of the same. It could also be a phosphorus deficiency. Get something with a low N and high PK and feed it in. Might not correct it, but should stop it from progressing until you are ready to harvest.

 

[Mañ'O'Green]

@Greengrower Your PH is way too high It should be 6.2 - 6.3 and like others have mentioned your not feeding anywhere near the balance of nutrients you need This is the BioBizz feed chart:

When you read down this chart for Biobizz Litght Mix Week 7 You should be feeding all of these:
4ml/L of Bio-grow or Fish-Mix
3ml/L of Bio-Bloom
1ml/L of Top-Max
4ml/L of Bio-Heaven
3ml/L of Alg-a-Mic
4ml/L ofActi-Vera
0.5ml/L calmag.

Some of you plants are showing signs of nutrient burn (toxicity) are you fertigating to ~15% run-off?

You really should know more about your water. Is it sanitized with chlorine or chloramines? What is the starting PPMs

Fix the PH first by lowering it to 6.4 today then 6.2 the next time you fertigate. Get the rest of the nutrients you need an feed those girls!




.

 

[Greengrower]

@Greengrower Your PH is way too high It should be 6.2 - 6.3 and like others have mentioned your not feeding anywhere near the balance of nutrients you need This is the BioBizz feed chart:

View attachment 1192461

When you read down this chart for Biobizz Litght Mix Week 7 You should be feeding all of these:
4ml/L of Bio-grow or Fish-Mix
3ml/L of Bio-Bloom
1ml/L of Top-Max
4ml/L of Bio-Heaven
3ml/L of Alg-a-Mic
4ml/L ofActi-Vera
0.5ml/L calmag.

Some of you plants are showing signs of nutrient burn (toxicity) are you fertigating to ~15% run-off?

You really should know more about your water. Is it sanitized with chlorine or chloramines? What is the starting PPMs

Fix the PH first by lowering it to 6.4 today then 6.2 the next time you fertigate. Get the rest of the nutrients you need an feed those girls!




.

Cheers for the info!
I have that chart, just didn't want to invest so much into all the nutes so just went with the basics, might have to bulk out my byte collection. I don't water to run off because biobizz recommended not to. I actually never payed attention to the pH part there lol. I just went with genetic uptake charts and thought I was in an okay range.
However biobizz say not to adjust pH as the soil buffers it?
Thanks again for the input!