weird yellow spots close to harvest.

hey all, am new to writing but have read and used the info in alot of threads off this site and has helped alot..
But ive run into a problem that i cant find a solution too or at least diagnose .
im about a week from harvest but a whole lot of yellow spots have appeared and are spreading rapidly iv tryed cutting the leaves to stop the spread
but that hasnt worked also flushed them out with water (also didnt work),and i dont think it has anything to do with the ph levels as have done a home test with the soil using Vinegar and baking soda and neither fizzed or bubbled ,so im really not sure whats going on,
PPPLLLLEEEEAAAAASSSSSEEEEEE help
heres some pictures too help too..

You are fine, don't sweat. You've got some burning and lockout, but flowering is the death cycle. However, you are not ready to harvest in a week if these photos are from today. I'd guess at least three more. Don't worry about fan leaves this late, they get purged and water + potassium if possible and just be patient. They can be allowed to get ugly late in flowering (the death cycle) and your product is completely safe. Flushing for flushing is bad, as overwatering can produce mold and attract pests. Play it by ear, and remember that these things grow wild with no problem; yours will be fine as well. Good job so far, and good luck! PM me if you want 1 on 1 advice.

You can't test the pH doing that, but my guess is that isn't the problem anyway. Looks like over fert potentially. You leaves look very green for close to harvest, the tips are a little burnt, and some leaves look a little clawed. All possible signs of too much N. Your buds look nice and sticky, though quite skinny. Are you under HPS? How many watts, and is it a sativa? Otherwise, the grow looks pretty good. If there's only a week to go then those few spots aren't even worth worrying about....the yield looks a little light though (unless that's just the photos) so I'm wondering what's up with that?

I'm with the green man! I'd also say they are weeks away from harvest...from the size of the buds alone. But those pistil are all brand new looking too..where are you getting your timings from? How long have you been flowering? Are you sure your room is 100% light proof?

cheers guys great reassurance haha, as for yeild theses are pictures of the lower branches as i trimmed the leaves with the dots on the main heads to try protect them.
they are set up under a 600w hps in a portable grow room inside my spare room and the lights are on during day time so no light should get in as i dont go into the room when lights off
theyve been flowering for 5 1/2 weeks now and they were 16/8 during vege and now on 12/12 during flowering,yes they are sativas but not 100% sure of the exact strain as there seeds i got from bags,and the pistils on the heads are about 20% browning and 80% white so thought they only had about a week to go but could be wrong. and cheers grnman will keep that in mind..
heres a pic of one of the heads

How hot is that room?

If you changed to 12/12 5 1/1 weeks ago then I reckon you should have at least 3 weeks left. Looks like a sativa/indica hybrid which may be fairly sativa-heavy, so that could mean even longer!

Something doesn't look quite right, and I think you need to keep a close eye on them...cos I think those pistils may be turning brown too early...always hard to tell from a photo, but sometimes that can happen because of deficiencies, rather than because they are properly matured.

Was at 25dgr celcius this morning but never goes over 30 and drops to about 15 over night..
Could it be because the last 2 waterings have just been water and no nutes as ive wanted to clean them out before harvest??cause in that case
they wouldnt be getting what they need which is matching up with what your saying ..