Only my second grow, and already things are going a bit dodgy for my little Mazars.

These are examples of the yellow patches and dead edges.
[attachmentid=128828] [attachmentid=128829]
[attachmentid=128833] [attachmentid=128831]
And these two shots show the bleaching affect
[attachmentid=128830] [attachmentid=128832]
Apologies for the color problems, HPS lighting, let me know if insufficient.

These poor babies are 21 days old, and have just been moved to the grow room for vegging. They're in 3" rockwool cubes in clay pebble-filled buckets, flood and drain. They've been in the grow room for 5 days, previously sitting under a 125W enviro. Light cycle 18/6. Temps a little high, 86 max 70 min. Humidity very low, around 20%, probably due to lack of proper extraction and intake. Grow room is just under 5 cubic meters, completely sealed loft grow, with a 400W HPS.

About a week ago, the biggest plant started showing yellow and pink/orange patches on its leaves. I put it down to under feeding as they were on baby nutes still and were about to go into the pod system and get fed proper Grow A and B.

When I moved them into the grow room, I noticed that two other plants were also showing signs. The nutrients used are House and Garden Grow A and B, set to an EC of 1.8 (including a base water EC of .7), which is a lot higher than what uk420 advocates (generally), but it was what I was told to do and the first grow went well. pH 6.1

Within two days, all plants were showing severe signs. All lower and middle leaves showed advanced yellowing or a bleached green, top leaves not so affected.

After searching uk420, I figured that they were suffering from nute burn.

So I drained half the res, topped it up with water, EC is now 1.2, pH 6.2

Plants seem to be a little happier. The lower and middle leaves still affected, but they seem to be reacting. The new growth starts off nice and healthy, but as it gets a couple of nodes lower it starts to get affected.

So, is it nute burn? Have I treated it sufficiently? Will the old damaged leaves recover or should I concentrate on the new growth?

Or is it something completely different? I've read the sticky self-diagnosis thread here, and come away with a different diagnosis every time!

Many thanks for your time and help...

Edge

Hi Do you have an ec meter? if so you can ask the plant what it wants,
There young so put em at an ec of 1.0 and if 24 hours later its gone down then they need food,
Go up in small steps 0.2, Once you have it right the ec will stay constant, If it climbs they want less food,
Also bubble or move your water for 24 hours it helps get clorine out a bit and will be more stable than out the tap, If in doubt dump the whole res never water it down, and never add just water add water and feed, Another tip is instead of horrid acid i use silica as ph up and calcium as ph down.
JS

Cheers JS. I have just got a new 100L master reservoir which I am going to hook up, where I will have the luxury of letting water sit for 24 hours. I am also thinking of installing reverse osmosis for it too, as a base EC of 0.7 is very high.

Good tip on monitoring the nutrient feeding, I'll start that tonight. And I'll drain and refill the tank with fresh solution, you're right, I think I was being a bit lazy there...

But I've started second guessing myself, and am concerned that its not nute burn, maybe a magnesium deficiency. Is there any harm in spraying with epsom salts just in case, or could I make the nute burn worse?

Calcium as pH down? Sounds great! I've done a google search on it and come up with nothing. Can you give me some more info? Such as what form the calcium takes, doseage and supply options?

Are you using hard water nutrients edgeworth?

Hey VRG,

Um, sorry mate, no idea what you're talking about. Didn't realise there were hard (and presumably soft) water nutes. I've done a quick search on the House and Garden nutes, and nothing is being noted, so I would assume not.

Hard water affects the pH level, doesn't it? I'm trying to keep it down to the 6.0 mark, but its a bit of a struggle, truth be told.

H&G do both HW and SW nutrients!

Your tap water is very hard! I would personally say too hard!
I would install an RO system, even with a HW nutrient you will forever struggle with your poor water quality.

Your problem lie's within your water.

VRG

Cheers HGV, I knew the water was hard but I didn't realise it could do this much damage.

Will look at the RO, another £100+ "invested".

Mind you, I'm having more fun with this than any other use of my time at the moment, and a hundred knickers to keep my little greenies happy had got to be worth it.

Have just had a look on Screwfix, they have something called Scale Reduction systems. Are they good enough? About a third of the price of the RO...

The H&G nutes were bundled with my system purchase, didn't really have much choice about them.

EDIT: Looking at RO systems now. Whats the smallest system people would recommend? They seem to start with a 2 stage system costing about £50, and go up to a 6 stage system costing about £150. Any pointers?

Cheers, Edge

You dont need to spend a hundred pounds on one, have a look here!

Check your H&G A&B bottles, they will tell you if their HW or SW. If they are HW, and you do get the RO unit... bin them and get a SW nutrient.

Just found that same site, VRG. Any pointers on the smallest I can get away with? Am tempted by the 6 stage with inbuilt TDS guage (£145), but if I can safely use the 3 stage £65 job, that would be great.

Ive never used one, tho' im sure some members on here are using the £65 model. You need to look at how much RO you need to filter each day, and base your purchase on the output in litres.

Many thanks for the pointers VRG, I'll post a new thread and see what happens.

Edge

sorry to hijack your thread edgeworth

but i think it's a relivant question which may help us both.

i also live in a HW area PH 7.8 and an EC 0.6

i heard/read somewhere that out of the 0.6 atleast half of this number was dead salts or something.
so that if you wanted an EC of lets say 1.0 you would add 0.7 of nutes giving you a reading of 1.3 but infact is more like a true reading of 1.0?


i'm still a little unsure of how true this is but i'm hoping some of the more experianced growers out there can point us in the right direction

hope they pull through for ya chap

ATB Clueless

No worries Clueless, help yourself!

I was given the same advice. Followed it for my first grow, and didn't have any problems at all. This is my second grow, and unfortunately it doesn't appear to be helping at all.

I think I'm going to fork out for an RO kit, that way I can save my poor brain the complications of dividing by two...

Good luck to us all, Clueless...