? about ph?

[marleycoalby]

I have a couple of ? about ph.I have seen signs of def. and don't think it is due to low nutes.I wonder if it is from low ph.I have an ebb&flow system with a 70 gall. rez.When I check the ph I put my meter in the rez. until I get my reading which I try to keep at about 6.I ran some distilled water through a pot and came up with a reading of 5.36 when I checked my rez. it said 5.85.Should I always expect a little deviation with those 2 readings?Should I always adjust a little higher than wanted?I have a nice hanna ph meter and want to try and get my ph problems figured out.

[nuggdigger]

If you want your pH to be 6.1 then why would you set your reservoir to 5.85?
If you want your pH to be 6.1 then set your reservoir pH to 6.1 and go from there.
Yes.the deviation can be explained..there were variables and the change is nominal..
Setting your pH in your system (media/table/pots..etc)is an initial conditioning step..but you can work your way there. Just quit fighting it, and go with the flow.

peace

[marleycoalby]

I do seem to be fighting it.I definitely have some kind of def. or nute. lockout.I set my rez. to 6.0 and try to keep it there but it still seems to be off.I checked that by running distilled water through my plants to measure it.What I got was almost 1 point lower in the plants than my rez.I am just curious if I should plan on keeping my rez. about 1 point higher than what I am shooting for?Here are some pics. of what my plants are doing if anyone sees what I am doing wrong.

[Stone]

You need to tell us what you're feeding them. All the particulars.

The bottom pic shows a clearcut case of Mg. problems.

[marleycoalby]

I have been feeding them gh nutes. at about 80% of what gh recommends.The only thing that I have been supplementing is botanicare cal-mag at 5ml per gall.I too thought it was either a cal def. or mag. def.I am also wondering if I am overwatering them

[Stone]

Definately not a Ca. problem. Not overwatering, either.

BTW, what is 80% of what GH recommends? And why not full strength?

[kruger]

hi

iron def no ?
you have a pest on your plant too , thrips or spider mite ..

and have you a high rate of humidity ? ( on the two first photos)
because I had a similar problem due to a high rate of humidity = pathogen (?)

(pathogen : sorry i 'm not sure of the term in English , in french it's "champignon" ,or "mushroom" in english )

++

[marleycoalby]

I have been using 80% of the recommendation because I was affraid I was over fertilizing them.The humidity is about 60%.I did have some whiteflies but they have been gone for awhile.I did think I had some kind of pathogen so I used a h202 flush to get rid of any pathogen.I have cut back on my water lately and it seems to be helping.I don't know about iron def. never had any problems in the past.If I have been using the same strain for 2 years making cutting over and over could that cause any problem?

[Stone]

Use full strength, as directed. It won't overfertilize them.

FWIW, I've been cutting the same strain for over ten years with no ill effects.