Rusty spots on leaves!!!

Mg deficient? Week 5 of flowering, S.A.G.E. Have other strains but only the sage is effected. Many leaves now turning bad like this. Pic is not so good but they get a rust color in the main vein and rusty spots all over. then they yellow and die. Please help.

600 watt HPS
Potting soil/perlite 50/50 mix in 4 gallon pot
PH 6.1
RH varies between 60 and 70
good air circ.
Temp 72 day, 65 night
TDS unknown
Nutes= fish emulsion and micro nutes thru veg. now only tiger bloom...afraid to add anything until this is solved.

Did you look under the leaf to see if it's spider mites? You may need a magnifier to see them

Here you go a handy reference

ElementDeficiency
Nitrogen Leaves turn a very light color and start to turn yellow starting at the base of the plant first. Plants growth slows dramatically.
Phosphorus Leaves turn a dark green or grey with blotches. Long term deficiency results in poor root formation.
Calcium New leaves never develop and stay small and dry. Long term deficiency stunts growth and causes poor root formation.
Magnesium Leaves turn yellow and develop brown spots but leaf veins stay green. Buds do not develop.
Potassium Leaves turn brown with dark splotches then yellow and they curl up.
Sulphur Leaf veins turn yellow and leaves become very dark near the stem of the plant.
Boron Stems become torn with brown tips and leaves become spindly.
Iron Leaves dry out and turn crinkly while veins stay green.
Manganese Leaves develop a mottled appearance and growth virtually stops.
Zinc Growth rate of plant slows or stops entirely.
Copper, Molybdenum and other trace elements Leaves turn dark brown and fall off.

Thank you Woodsmaneh for the ref chart! Not mites, have seen them in the past and the other strains in the room are fine. This is the first time I have done SAGE and am wondering if they need a higher PH. According to ur chart, Mg prob makes the rusty spots I see but veins stay green...oh well, only 3 weeks to harvest and they are LOADED with big sticky frosty buds. They will probably be okay. ( I pray)

check out this thread:https://www.rollitup.org/marijuana-plant-problems/150004-plant-moisture-stress-symptoms-solutions.html?highlight=brown+curling+leaves
or this one:https://www.rollitup.org/marijuana-plant-problems/38772-guide-diagnosing-plant-problems.html?highlight=brown+curling+leaves
prolly find ur answer in one of the 2.

Looks like either pH spotting or Calcium deficiency to me. The rust colored spotting is usually Calcium. Lighter colored spotting (whitish) is generally more associated with Magnesium. Judging by your pH at 6.1 I'm leaning towards that being the issue. Healthy soil pH is 6.5, Hydro is 5.8... You're stuck somewhere in the middle, which is an issue. Your biologicals that are responsible for processing and breaking down some of these nutrients need the right pH to keep doing their jobs.

Calcium deficiency looks like rusty spots because of how the element works in the plant. The energy cannot be moved away from the area on the leaf and as a result the chlorophyll literally over heats. Think of it like running out of Oil in your car. Eventually the engine seizes and catches on fire from the heat. The entire cell burns, which is why it is brown.

Magnesium deficiency looks more white because it is an element utilized by the chlorophyll for making the energy. If the element is in short supply the chlorophyll simply dies, which causes the plant to lose its pigment but without the burning. Thus, instead of a "burn" you just get a lighter colored spot from the absence of the green stuff.

That's how I understand it anyway.

I'm iffy with Tiger Bloom. I see a lot of sick plants on that stuff. Personally, I think all you need is the Grow Big and the Big Bloom. There are so many metals in the Tiger Bloom it makes me question the chelators they use to keep it from precipitating. Combined with the perlite (which can hold on to these salts and metals) this could create a different pH in your media than in you are feeding as a result of the build-up's influence.

Thanks, Snow Crash! The prob DID start shortly after using tiger bloom and I agree on the PH prob as well. Will stop TB and get PH adjusted. Only time will tell now.