What is this deficiency?

I'm in week 6 Flower, 2x sp-3000 in a 4x4, closest bud to light is 14inches, using Cyco full regime. First time growing this strain (cheese). First time I've had any deficiency with Cyco.
BlueLab pulse meter says 1.6 EC. They are in a 30L airpot drinking about 4-6L/day, it's been varying in the last week.
This whitening in the veins (not between them) appeared about a week ago along very few brown spots. Can't find anything describing whitening of the veins themselves.
Any help appreciated.
edit: forgot to add. growing in coco, temp 24 (ac comes on at 25.5), RH = 55% creeps up to 60 occasionally before dehumidifier brings it down.

be sure shes dry. be sure the ph is correct. add 1 drop per cup of superthrive and water. I also recommend cutting in some worm castings before watering. The give it time checking your new leafs for for improvement. Then go from there.

Can someone say CalMag?

Calcium

What type of water are you using?

Keep an eye on your light distance. The SP3000 produces 1000 umol at 19.5", 14" would be ~ 1900 umols, likely too intense.

Billy the Mountain said:

Keep an eye on your light distance. The SP3000 produces 1000 umol at 19.5", 14" would be ~ 1900 umols, likely too intense.

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Thanks I have raised the light.

Mattcheck said:

What type of water are you using?

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RO

HighLife4Me said:

Can someone say CalMag?

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I've never had calmag issues with cyco before. They dont have a calmag additive.

Using RO water if your nutes don't have a cal mag in it you will need to add some. RO removes calcium from the water.

Looks like Cal deficient, can be caused by salt build up usually ..

Thanks everyone. The lights were far too close for this strain. My previous grow was white widow and they loved that height. Everything looking good now.

Your feeding to runoff once or twice a day?

Pretty dark green in that one pic.