Rusty spots

[Atulip]

Problem: Looks like Ca problems. Rusty spots on older leaves.

Medium/grow method: Rockwool starter cubes in 3 inch net pots with hydroton, in a closed flood and drain table.

Feed: and supplements used: MegaCrop 2 part, 350ppm 5.8pH

water source: 0ppm RO

Strain/age: Mephisto Skywalker x Forum Stomper 7 days above ground.

light used: 3500k cree cobs about 2 feet away.

Climate: 75°F-81°F 40-50% humidity

Additional info: Sterile grow, 1mL/gallon 34% h2o2 in the reservoir every 3 days. 24/0 lighting


Ignore the dying clones, it's the seedlings I'm worried about.

Enclosed flood and drain table, floods about 1/8 inch into the net pot every 2 hours

Small spots on the first seedling

Much more visible on the second seedling

 

[Mañ'O'Green]

Looks like a PH problem to me? When was the last time you calibrated your meter? What is your ratio A:B? I would also add Botinicare HydroGuard to your reservoir.

 

[Atulip]

Looks like a PH problem to me? When was the last time you calibrated your meter? What is your ratio A:B? I would also add Botinicare HydroGuard to your reservoir.

Calibrated a month or so ago. And about 1 part A to 2 parts B right now. Would hydroguard be necessary since I'm running h2o2 sterile?

 

[Mañ'O'Green]

Calibrated a month or so ago. And about 1 part A to 2 parts B right now. Would HydroGuard be necessary since I'm running h2o2 sterile?

Check the PH meter again as it is due. No you cannot use HydroGuard in a sterile system. I personally had nothing but failures in sterile hydro.

Your nutrient balance is way off.

You need to get some NPK Industries RAW B-Vitamin (mostly Epsom Salt) and Potassium K to balance out the nutrients at the lower PPMs. when mixed at the higher PPMs for photoperiod plants the A&B parts eventually reach a balance as the product is based on Photoperiod plants.

This will give you a much better nutrient profile.

 

[Atulip]

Check the PH meter again as it is due. No you cannot use HydroGuard in a sterile system. I personally had nothing but failures in sterile hydro.

Your nutrient balance is way off.


View attachment 1371301

You need to get some NPK Industries RAW B-Vitamin (mostly Epsom Salt) and Potassium K to balance out the nutrients at the lower PPMs. when mixed at the higher PPMs for photoperiod plants the A&B parts eventually reach a balance as the product is based on Photoperiod plants.

This will give you a much better nutrient profile.

View attachment 1371302

I've ordered a big ole bottle of calibration solution this time instead of the little packets, so I can calibrate more frequently. Gonna give your feeding chart a try with the RAW nutrients as well. In the meantime I've bumped the pH up to 6.0 in case that's the issue. Thank you for your help.

Would that be the ratio of nutrients to use for an entire grow?

 

[Mañ'O'Green]

I've ordered a big ole bottle of calibration solution this time instead of the little packets, so I can calibrate more frequently. Gonna give your feeding chart a try with the RAW nutrients as well. In the meantime I've bumped the pH up to 6.0 in case that's the issue. Thank you for your help.

Would that be the ratio of nutrients to use for an entire grow?

No, the reason behind the two part product is so you can change the ratios of NPK throughout the grow. This is the schedule I am using in my current grow. The yellow highlighted line is the week I am in now. read closely as the water volume changes in the beginning until I am on the reservoir.

 

[MassMom]

I have fooled around with the idea of mixing up a solution that is "in balance", pH'ing it to 5.9....then just diluting it down to the PPM I need at different stages of the plants life.

 

[Bob's Auto's]

I have fooled around with the idea of mixing up a solution that is "in balance", pH'ing it to 5.9....then just diluting it down to the PPM I need at different stages of the plants life.

Adjusting pH is best done after diluting it. The lower pH in the high concentration solution can make some chelated elements drop out of that solution. Rendering the recipe unusable...

 

[Atulip]

pH was a little low when I calibrated my meter. Corrected the pH and have maintained it between 5.9 and 6.1, and changed the nutrient mix to week 3 in MoG's feeding chart using Megacrop A, B, Raw b vit, and Raw k. This was 8 days ago and the issues still seem to be progressing.


Here they are at Day 17, issues corrected and they were topped and trimmed

SxFS 1

SxFS 2

Here they are today
Day 25

SxFS 1

Older leaves

Middle leaves

SxFS 2

Older

Middle

@Mañ'O'Green

 

[Mañ'O'Green]

The new growth looks good but it looks like your PH is getting out of range? How often do you check it?