Growers ark hard water hydro custom feed

[Jay87]

Hi every one.

A post to any growers ark users. Basically Iv had a custom feed made to suit my water. I’m having issues with slow stunted growth. Plants look very dark green in colour, and have purple stems and very woody. I’m in nft trays. The thing I’m struggling with, is they say to use 3ml a litre to start with which would make my ec around 1.6. Iv started on less because to me to start them on this strength would burn them normally. And as they look dark green makes me think they are getting too much. Any help would or advice from people using this would be great. Thanks.

 

[Oldguy71]

Sounds like a phosphorus deficiency. Hard to say without pictures. I’m betting it’s caused by ph problems. Have you calibrated your ph meter recently? Phosphorus uptake is best at the higher end of the ph range, 6.1-6.3 ph.

 

[Jay87]

Sounds like a phosphorus deficiency. Hard to say without pictures. I’m betting it’s caused by ph problems. Have you calibrated your ph meter recently? Phosphorus uptake is best at the higher end of the ph range, 6.1-6.3 ph.

Hi thanks for the reply. This is what I was thinking. Sounds like phosphorus or mag. But I don’t know which one. My ph has been spot on. I go in at 5.5 and it rises to 6.1 to 6.3 area. Yes i have checked my ph pen for ec and ph and is calibrated correctly. I’ll load some pictures now. I know the strain must be fussy, because I have a mother in bio bizz all mix and it’s doing the same thing. Dark in colour with red stems. Don’t know where to go from here. Should I flush?? Then go back in with nute and some phosphorus? Any help appreciated.

 

[Oldguy71]

Maybe the hard water nutrients are light on phos thinking it would be made up by phosphates in the water? I’m not seeing mag def symptoms. What makes you think it might be mag?

 

[Jay87]

Maybe the hard water nutrients are light on phos thinking it would be made up by phosphates in the water? I’m not seeing mag def symptoms. What makes you think it might be mag?

Here is the npk. I thought that was a bit low on phosphorus? It’s a long story to think it’s mag. Basically I used to get the same issue with the other feed, added cal mag and it used to sort it out. But because of it being a custom feed to suit the water, I shouldn’t really be having to add anything else? This is why I went with a custom to illuminate deficiency’s, but still getting this same damn problem. I sent a water sample, an I know the water has very high calcium in it. It’s coming in at 850 ec very hard water. Do you think I should add some phosphorus on the next change? If so what strength? 1/4 or 1/2.

 

[Oldguy71]

I think I’d add a 1/4 dose of extra phos next feeding. Your ratios look fine. Could there be something blocking or competing with phos up take? I think silica competes with it.
Looking at your pictures more closely I see some slight mottled yellowing on a couple leave, not really inter veinal but might be related to a mag def. Maybe hit them with some Epsom salts too. I think one tsp per gallon is recommended but you should double check that before giving it to your plants.

 

[Jay87]

I think I’d add a 1/4 dose of extra phos next feeding. Your ratios look fine. Could there be something blocking or competing with phos up take? I think silica competes with it.
Looking at your pictures more closely I see some slight mottled yellowing on a couple leave, not really inter veinal but might be related to a mag def. Maybe hit them with some Epsom salts too. I think one tsp per gallon is recommended but you should double check that before giving it to your plants.

Sorry for late reply been so busy with work and other stuff. So I gave them the 3ml a litre and they began to bounce back. Best growth Iv seen yet. But they are starting to go wrong again. Basically this is what I done.

The 3ml a litre got me to 1.6 when I filled up my res. Overnight it dropped to 1.4 and has slowly drifted down to 1.3 over 4 days. Ph has risen from 5.5 to 5.9 over the four days also as they are drinking a fair bit. I’m stuck on what to do now. I will change my res tonight for a fresh batch at 3.5 ml a litre which I know will drop tonight by at least 2.

Do I add more nutrient to res to bring it back up? How much do I add? To me I must be under feeding. But I’m chasing them and can’t seem to catch up. Thanks.

 

[Oldguy71]

you can add more nutes to the res. If it were me I’d add more nutrients to bring it back up to your target ec every 24 hours until the ec stops dropping. If it’s still dropping after a few days I’d start raising the target ec a couple points until you find the balance.

 

[Jay87]

you can add more nutes to the res. If it were me I’d add more nutrients to bring it back up to your target ec every 24 hours until the ec stops dropping. If it’s still dropping after a few days I’d start raising the target ec a couple points until you find the balance.

Thanks a lot for the reply man. I get what you’re saying. That’s what’s so hard at the moment Because I don’t know what my target ec should be. Im know roughly but then go in at that and they just take so much. That’s what’s making it so difficult. This is what I will try and see how it goes. So to add more nutes, I will use 10 litre bucket to mix the a+b first. Do I just add what I’m already giving then? So like 3.5ml to the 10 litres I’m going to top up with? Thanks for the help. Really appreciate it.

 

[Oldguy71]

I don’t think 1.6 is that far off because after that first big drop it took a few days to drop another point. Maybe 1.7 is where they want to be or it could be 1.6 and they’re just making up for the time they were missing a key nutrient.
To top up your ec. Add 5-10 mils of an and b to your res and see where you’re at. If it’s low add more a/b until it’s at 1.6 or 1.7. Or you could mix up a 2 or 2.5 ec batch and add it to the res until it comes up to 1.6 or 7