plants leaves yellowing and starting to brown

[thecalm007]

homemade 10 gallon had 5 but 4 plant dwc system with square plastic pots i put holes in and cardboard covering up hydroton and rockwool cubes...3cfls....1 1000w hps light....3part gh flora series....ppm 795 (using lucas formula)..ph 6.0 according to liquid ph pen ...... it has been 3 weeks and 5 days from bag seed planted ...1 in the middle where i think it is getting the most aeration is the tallest 8 inches and the others are 3.5 to 7 inches...i think also where the light hits is why the others is smaller....because i don't have my vent fan yet and other things for my closet i cut my hps light on periodically throughout the day until temps rise then cut it back down...my leaves on some of the plants have lighter green spots some of the bottom leaves are turning yellow and the one plant i threw out had bad browning spots on them...I feel like it's a mag def. also the fisrt week of having them in my dwc tub the ppm never went down and the ph rose had to ph down ..did my first res change and ph was perfect....

 

[funkfarmer]

What kind of water(tap or ro)? How close is your light? How high is the water on the lots, are they getting water and nutes? I think your ppms are a bit high for seedlings ,could be nute burn.

 

[thecalm007]

checked my ph through out the day and it stayed perfect. the first week of being in the res i had the ppm set to 400 minus the ppm of my water did not use the lucas formula. for this 2nd week i did. the first week however i never saw my ppm change. it never went down neither did my water. for this 2nd week it looks like it's doing the same thing thou it has only been 2 days. i would luv to here the communities thoughts on this ...i have read alot on the problem charts just would luv other opinions....

 

[thecalm007]

i am using cfl's and they r about 2 inches above light ...i think i have realized a major part of my provblem. my rockwool cubes were soggy I think i had them to far sown in the pots. poor aeration in the water i believe and today i finally got the guts to check the plants in the hydroton and i seen brown stuff on the rockwool all but one and i think i developed root rot due to poor oxygen in the water and the cardboard covering up pots trying to keep light out(duhhhhhh) they looked reallly green thou otherwise. I wish i would have put up picsbecause i just through out 3 of the four i had left because of the rot and maybe i didn't have to(including my biggest one. but for how big it was on the top i felt like it should have had more roots than it did. So for the one left that had no brown on the cube i cut some of the tiny brown roots it had moved it to a bucket sytem i purcheased which the pump came with and praying that she (hopefully) surives. another ? what is the avge. of a 3 week old plant from seed

 

[thecalm007]

thnx funkfarmer for replying i here ppl saying to count your weeks from 3sets of true leaves. being as thou i am new i am trying to get a hold on the basics of it all....one more question ....being as thou i have just trimmed some of my roots with the brownish color should i lower back my nute dose until she is healthy.....and could the brownish color on my roots be from the nutes....any info from the u and the rest of the community very helpful!!!!

 

[thecalm007]

tap water ppm 180 to 200

 

[funkfarmer]

The brown color could be from your nutes, if it were root rot it would also smell. I would back of the nutes altogether until you see her with new growth. Your tap water ppm is kinda high, maybe you should buy some distilled.

 

[downdon]

Maybe this strain does not like the LUCAS FORMULA. Try giving some grow nutes and add some cal mag.

 

[Matto]

I think root rot has started and need more oxygen for seedlings.

 

[realtalk]

leaves turning brown on the tip sounds like nute burn lower ppms.

 

[altitudefarmer]

I believe the GH Flora series needs to be supplemented with magnesium and/or sulphur. Look up these deficiencies in Jorge's Medical Grower's Bible and see if your plants match the deficiency descriptions.

 

[stardust]

I have the same issue, its never happened before, i just started querkels they are in their second week of flower and their bottom leaves are yellow in the middle (not at the tips) and they have lots of brown spots.. its also strain specific because my other varieties are doing really well..no yellow etc.. i also feed them flora nova bloom and add the calmagplus from botanicare..could it be MG+ deficiency thus K+excess?? I took some close ups..ill load them up next.. maybe didnt shake the flora nova that thirly?? maybe i have root rot too..ill go check..hope not...i have growdan chunks and that holds 90 percent 02..soo. i should be fine with that root rot scenario specially since i have a DTW system..and they hardly linger wet..anywya....thank you for your advice farmersss.peace.