Beginner needs help with slow growth

[mad doctor]

This is my first grow in a DWC setup.

I have a 4 pot setup with with a reserve. It totals 16 gal.

I have lost 3 plants. So I'm down to 1 with 8 gal of nutes.

I'm using general hydo flora nutes, Root Excelurator, calmagic with RO water.

I'm using 1 x 600w MH light. I had 1 LED at the start but changed to the MH.

Tent is heated to 71 deg. Water is at 64 deg. Ph is 5.4-5.8. PPM is 750 - 980.

One clone arrived not looking well and died not long after I received it. They I had root rot so I up the Root Excelurator which fixed the problem. Then I cooked 2 with the lights.

So I'm now left with 1 plant which after almost 6 weeks is only 6" tall. I only have 2 long roots from the basket. It is slowly changing color from yellow to green.

At the moment I have about 1/5" of growth a week.

Any help would be amazing

 

[iwltfum]

How strong is your pump? usually its written on the side in liters/hr or gallons/minute or something like that.

 

[mad doctor]

Water pump is 800L/H

Air pump is 5100L/H with 2 x 10" airstones per bucket

 

[Dr Fish]

When's the last time you calibrated your ph meter??

 

[mad doctor]

I just checked my Ph meter with both 4.0 & 7.0 solution. It was perfect. Should I mist the leaves or add water to the block till more roots grow?

 

[OldMedUser]

Your specs all look perfect for good growth Mad Doctor.

She looks like she has multiple nutrient deficiencies which is usually from having the pH all out of whack or too much of some mineral like iron in the tap water but you're using RO so that's not it.

Are you sure there isn't some root rot lingering. It can kill all the fine feeder roots that are needed for the plant to absorb and convert the nutes so the plant can use them. The main roots can still absorb water so that's why it might still be standing but living off it's stored nutes as it slowly dies.

I would suggest greatly reducing the amount of light to let it try to grow new roots instead of trying to grow more plant tissue. Like a cutting needs low light at first so it can concentrate on sprouting roots instead of growing more top. Might not hurt to foliar feed it a bit while you do that. Just take a bit of nutes out of the rez and mix it 5:1 or so with water and give it a good wetting just before light's out for a few days.

Good luck!

L8r

 

[Tead]

Then I cooked 2 with the lights.

Is this the lone survivor of the 'cooking'? Has it looked like this since the 'cooking'? Is the new growth coming up from the middle green and good?
I've cooked a lot of plants in my day and your photos sure remind me of a good cooking. Some can start growing again, but I've cooked many to death. If this is the survivor, I'd say she looks pretty good for being cooked. If you've got active growth that looks ok, then you've probably corrected the problem.
I like OldMedUser's advice.... treat her more like a new clone.... lower light, lower nutes. She's got a lot less active leaf mass now and is more like a clone than a small plant.

 

[mad doctor]

She has come a long way since the cooking.

She has had a few growth spurts but after a few days she stops again. I cant see any change in here environment during the spurts.

I have lifted the 600w MH to 27" above her till I get some fluorescent lighting. I've started misting with 5:1 solution. I'm only using 1/2 tsp per gal of each of the 3 GH nutes.

Thanks for the help

 

[mad doctor]

So I changed the light to a double T8 fluorescent and it sits 4" above the plant. I'm due for a water change so I will do that tonight.