Rust on lower leaves

[JamesJoyce]

Hello,
Away from plants for two days and when I got back I see lower leaves getting rusty and some crunchy and dead...

I am growing in soil with quantum boards and cob leds mixed. Never used any nutes except rhizotonic. 6 inch extracted 4 inch intake fan. I assume a fungus problem due to high hummudity because I did not use any ventilation fan and the plants do not drink much... Hummidity staying at 60s. Also I am getting 18 degrees when lights off and 25 ish with lights on.

2 plants in the tent are affacted they re on day 30 from germination. Mostly on lower leaves. Checked the back of leaves but I have nothing to zoom in... Saw some black spots but there were 1 or 2 which might be small soil particals from the pot.

Wanted to ask for more views before I take the action...

[M_C]

It may be time for some feed?

[JamesJoyce]

Maybe
In case I ll add some cal mag to the feed and see how it goes. Arranged a ventilation fan also and backed up the lights some.

[Forest]

as you are growing under qb/cobs up the temps to 28c and give extra mg its needed and your woes will sort them selves out , some feed would help or is there a reason for none?

air changes is needed you plants need to breath think how would u fair in a seal room? much the same for the girls

[Shreder]

Not a soil grower
But why add calmag and not your base fert?

DWC Bag Seeds / White Widow and King's Kush / Auto Blackberries / GSC, GZ, LSD (Mentored by Bud Lightyear)

[Forest]

Not a soil grower
But why add calmag and not your base fert?

DWC Bag Seeds / White Widow and King's Kush / Auto Blackberries / GSC, GZ, LSD (Mentored by Bud Lightyear)

super soil at a guess

[Shreder]

super soil at a guess

Yes probably. Just burnt the f of a rosemary plant in a supersoil cuz i gave it a feed from the grooms res XD

Not used to ferted soils smh

DWC Bag Seeds / White Widow and King's Kush / Auto Blackberries / GSC, GZ, LSD (Mentored by Bud Lightyear)

[JamesJoyce]

It is canna pro soil having enough nutes in till veg. Adding cal mag I think mag issue occurs when doing it under powerful leds

[Shreder]

Not doing leds but did hear some folks here having tricky mag issues under LEDs

DWC Bag Seeds / White Widow and King's Kush / Auto Blackberries / GSC, GZ, LSD (Mentored by Bud Lightyear)