Nutrient Burn and Magnesium Deficiency? HELP!

Hi everyone this is my first hydroponic grow and also the first time I've run into problems along the way

I'm growing 4 plants under a 400 watts MH light and two 125 watts CFL's, planted in rockwool cubes in clay pellets and using Sensi Grow from AN as Nutrients.
Unfortunately I blew all my budget on the lighting and hydro system so I didn't have the money to buy a PPM meter...

I'm seeing what I think is nute burn because I tried to fix a mg deficiency on one plant, I'd like to know if I'm right or it's something else entirely.
I already diluted the nutrient mix and ordered some Epsom salt (hope it works... ?) but I'm concerned because I did not see any improvement right away, is this normal?


Here are the plants showing problems:



Hope someone can give me some advice if I'm doing everything right or what I should change.

Flush with an EC of 0.8 then raise the ec slowly to 1.4 ish for plants that size what ph are you running it at you wont get good results in hydro without a ph meter or ec meter i have learnt from that mistake twice

i think there is no mag def its just over fertilised and possibly a bit of nutrient lock out due to high salt content (high EC ) use the chems at a quarter dose to start of with and do go over half the strength when there established will be much safer without an ec meter and what system are you using?

mckenzie41 said:

Flush with an EC of 0.8 then raise the ec slowly to 1.4 ish for plants that size what ph are you running it at you wont get good results in hydro without a ph meter or ec meter i have learnt from that mistake twice

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The pH ranges between 5.5 and 6.5 since I was using a dry pH down and it's hard to measure out same quantities
Thank you for the advice, hope it works

mckenzie41 said:

i think there is no mag def its just over fertilised and possibly a bit of nutrient lock out due to high salt content (high EC ) use the chems at a quarter dose to start of with and do go over half the strength when there established will be much safer without an ec meter and what system are you using?

Click to expand...

I thought there might have been a mg deficiency on the Zamaldelica plant because I was feeding them at a 1/4 strength when she started to show interveinal chlorosis so I upped the nutes, my mistake.
I'm using a top feed system, on a 6 times a day watering cycle
I hope to get an EC meter next week...
Thank you for helping

They look good to me so I wouldn't be too worried at this point.

BigEasy1 said:

They look good to me so I wouldn't be too worried at this point.

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I guess I'm giving them too much love

im finding that the ideal ph range is 5.5 to 6.2 although the growth seems to slow down after 6.0.

mckenzie41 said:

im finding that the ideal ph range is 5.5 to 6.2 although the growth seems to slow down after 6.0.

Click to expand...

I'm trying to keep it at 5.8