help asap 1st time grower

[sirgalot]

please help having problems
third week in flower
2 x 20ltr rdwc buckets
1 x rdwc res outside tent
all have air stones
1 x 600w mh 1 x 250w son t pro
1.2 x 1.2 tent
1 x 5" inline extract fan
1 x 4" fresh air inlet fan
2 x circulating fans
ph 6
tent temp 85/90
res temp 65/70
nutes greenhouse seed company all in one powder
buddas tree supplement quarter ml per ltr first use 2 days ago
dutch master zone half strength
checked my roots two hrs ago all fine no rot or slime

my plant is third week in flower ( 12/12 ) and the leaves that are at the top of the stem (near the flower ) are turning brown mainly on three stems. the brown seems to start at the base of the leaf and work its way to the tip i had nute burn on thurs so changed nutes to half strength a day later with the buddas tree.
what is causing this there is no other sign on any of the other leaves ( yet ) or on the lower leaves just the ones surrounding the flower.
should i flush with plain ph` ed water and start again.
would it compromise the grow if i changed to different nutes
please help asap

 

[Kola320]

I would flush and get your heat down I run my room no higher than 80.
How far is your light from the top ?
I'm not familiar with the nuts but you should be able to change them just do so slowly. I run the lucas formula and have had good results. hope you get her to bounce back.
Can you post a pic might be easier to tell ?

 

[sirgalot]

hi thanks for the prompt response my 600w light is 15" from top of the plant did the hand test and no way too hot for me ( less im dead and cant feel anymore )
cant take pic as i took them off for a precaution measure but if it carries on i will post one
kind regards