Help identify marks on leaves, stunt grow

[clash]

Hi,
I am growing second time in 2x2 tent. Having issues with slowed growing rate, and few flowers with little amount of pistles.
Days from germination: 45.
Strain: Auto Northern Light.
Light: 18/6. vipar xs1500 pro 50% dim.
Medium: 70% soil 30 % coco.
Water PH: In 6.0, runout around 7.5.
Trainig: LST.
Feeding: First 10 days watered with filtered RO water, no nutrients. After that started giving 25% of Tripart HW nutrients according to charts but with tap water with 200-300 PPM.

After the last feeding with full "preflower" dosage of Tripart HW but with 1L RO water, next day appeared light brown marks on foliage. Could it be cal mag deficeny or something else? Help these girls to have a nice harvest

 

[Creeperpark]

Hi,
I am growing second time in 2x2 tent. Having issues with slowed growing rate, and few flowers with little amount of pistles.
Days from germination: 45.
Strain: Auto Northern Light.
Light: 18/6. vipar xs1500 pro 50% dim.
Medium: 70% soil 30 % coco.
Water PH: In 6.0, runout around 7.5.
Trainig: LST.
Feeding: First 10 days watered with filtered RO water, no nutrients. After that started giving 25% of Tripart HW nutrients according to charts but with tap water with 200-300 PPM.

After the last feeding with full "preflower" dosage of Tripart HW but with 1L RO water, next day appeared light brown marks on foliage. Could it be cal mag deficeny or something else? Help these girls to have a nice harvest

You are doing good and have a good start friend. Thanks for posting. If you use RO water you need to buffer it with cal mag or your pH will drop very low in the substrate. It's best to maintain a steady EC from the beginning with every watering. Use a low ppm of fertilizer with RO water buffered with cal mag. If you stop and start nutrient EC or change the waters the plant will be stressed and may crash. Your problem here is you flip-flopped from feed to no feed and water changes during the grow. Maintain a steady EC and pH from the start by doing the same thing throughout the whole grow.

 

[DARKSIDER]

Hi,
I am growing second time in 2x2 tent. Having issues with slowed growing rate, and few flowers with little amount of pistles.
Days from germination: 45.
Strain: Auto Northern Light.
Light: 18/6. vipar xs1500 pro 50% dim.
Medium: 70% soil 30 % coco.
Water PH: In 6.0, runout around 7.5.
Trainig: LST.
Feeding: First 10 days watered with filtered RO water, no nutrients. After that started giving 25% of Tripart HW nutrients according to charts but with tap water with 200-300 PPM.

After the last feeding with full "preflower" dosage of Tripart HW but with 1L RO water, next day appeared light brown marks on foliage. Could it be cal mag deficeny or something else? Help these girls to have a nice harvest

Whats your temperature in tent maybes needs raising ..

 

[clash]

You are doing good and have a good start friend. Thanks for posting. If you use RO water you need to buffer it with cal mag or your pH will drop very low in the substrate. It's best to maintain a steady EC from the beginning with every watering. Use a low ppm of fertilizer with RO water buffered with cal mag. If you stop and start nutrient EC or change the waters the plant will be stressed and may crash. Your problem here is you flip-flopped from feed to no feed and water changes during the grow. Maintain a steady EC and pH from the start by doing the same thing throughout the whole grow.

Appreciete your attentation for my issue. Will follow your advices. I am planning to add TA CalMag supplement (2ml/l) for my RO water. Coco in my substrate is only an addtion, so I am not sure how to treat it and I am afraid to overfeed. Is it good watering schema: feed, water (RO with CalMag), feed, water...? What these marks on leaves are sign of, deficiency, toxicity or just not stable watering solution stress overall? Today the leaf from the first photo dried and curled upside even more, stem became weak, light to flex. Thanks in advance!

Whats your temperature in tent maybes needs raising ..

That's true. First 40 days daytime average temp was 21-22 C. Now is around 25-26 C, hope this will be more stable till harvest.

 

[ResinousKingpin]

Do you water straight from the tap or will it settle for 24/48h? If not,do it. Chlorine in tap water can also cause this marks.

 

[PoweredByLove]

Hi,
I am growing second time in 2x2 tent. Having issues with slowed growing rate, and few flowers with little amount of pistles.
Days from germination: 45.
Strain: Auto Northern Light.
Light: 18/6. vipar xs1500 pro 50% dim.
Medium: 70% soil 30 % coco.
Water PH: In 6.0, runout around 7.5.
Trainig: LST.
Feeding: First 10 days watered with filtered RO water, no nutrients. After that started giving 25% of Tripart HW nutrients according to charts but with tap water with 200-300 PPM.

After the last feeding with full "preflower" dosage of Tripart HW but with 1L RO water, next day appeared light brown marks on foliage. Could it be cal mag deficeny or something else? Help these girls to have a nice harvest

Looks like phosphorous deficiency. If you pH isn't over 7 then you need more bloom food.

 

[clash]

Do you water straight from the tap or will it settle for 24/48h? If not,do it. Chlorine in tap water can also cause this marks.

No, I leave tap water minimum 24h before giving it to plants. I want quit using tap water, because I installed RO filter.

Looks like phosphorous deficiency. If you pH isn't over 7 then you need more bloom food.

My thoughts also were that this is P deficiency. I am always balancing water to 6.00 PH after adding nutrients, but runout is 7.5-7.8. I did flashing 6l per 12l pot with TA FlashClean, but PH in runout still 7.5. After flashing when soil dried, I fed preflower dosage from Tripart chart + TA Pro Bloom, RO water (not buffered with CalMag). And this marks appeared. Honestly, I discovered some leaves with similar marks before, but they were less visible. But I thought that with flashing, I started from "scratch", and while soil drying, plants starts stretching, and I thought issues solved.

My first run was with Auto Durban Poison, I had less growing "knowledge", but I run to harvest almost flawlessly. Plants started flowering on 31 day, and buds increased from day to day very confident. Now is 46 day and I can see very poor signs of flowers, and overall color of plants is very pale. I am not panicking, but want to decide a strategy to stick with

 

[Orange's Greenhouse]

You should never use straight RO water. It has nothing in it and will agressively suck solutes out of everything, damaging roots. If your tap water in unsuitable you can cut the RO water with a bit of tap or condition it with a little fertilizer.
It is best to give low doses of fertilizer with every watering opposed to on/off cycles. If you're afraid of overfeeding just start at a low concentration and then increase or decrease depending on that plants' look.
Is the your soil peat based? Then they added lime to it to adjust the pH. That is why you're seeing the high run off pH. Flushing it out won't be feasible and I don't see the point. It worked until now and by adjusting pH of the water you're using it wont get worse.

Your plants are looking ok. Do not fixate on minor issues and break things.