Possible Mg Deficiency

[h4ppyf4rmer]

one of my six plants in my RDWC system looks like it's starting to get a magnesium deficiency in my third week of bloom. some of the largest leaves are starting to show spots near the ends.

The reason I believe it's an Mg def is because the pH starts at around 5.8 and by morning it's around 4.6 which makes Mg unavailable according to the charts.

The first problem is trying to figure out why my pH is dropping so drastically over night during lights on time. I'm losing about 1.5 gallons per day of water, so my plants are drinking fine. My EC stays about 1.4 pretty much all the time.

I know it's really common for the pH to drop during bloom but I don't think my last grow dropped quite this much over the course of a day.

 

[h4ppyf4rmer]

Here are a couple of pictures

 

[sixstring]

thats quite a drop over night.what nutes are you using,maybe someone has exp with them. i would be inclined to raise my starting ph to 6.0 and my ec to 1.8-2.0 and see what happens with ph over the next few days,but i have been known to do some goofy shit haha

 

[h4ppyf4rmer]

thats quite a drop over night.what nutes are you using,maybe someone has exp with them. i would be inclined to raise my starting ph to 6.0 and my ec to 1.8-2.0 and see what happens with ph over the next few days,but i have been known to do some goofy shit haha

yeah, I've been checking in the morning before work and night after I eat my after-dinner CannaCookie... I usually raise the pH to 6.2 but I've been keeping the EC the same at 1.4. I'm using GH flora at a ratio of 1gro:2micro:3bloom. I'm also using Hydroguard every couple weeks for active beneficials. The drop this morning wasn't quite as bad, was 6.0 when I went to bed and was 5.4 in the morning.

I'm wondering if I should be using CalMag, I just hate adding more shit though, lol

my plants are looking really happy and green with lots of nice buds everywhere

 

[sixstring]

yeah i did a few runs with gh.kinda remember using a weird combo like 2-3-2 g-m-b,so the micro has the most mag i believe maybe give a few bumps of that ? fuck man,thats why i gave up hydro,too many things to watch in the water,running soil you just assume its all good lol

 

[xenon730]

yeah, I've been checking in the morning before work and night after I eat my after-dinner CannaCookie... I usually raise the pH to 6.2 but I've been keeping the EC the same at 1.4. I'm using GH flora at a ratio of 1gro:2micro:3bloom. I'm also using Hydroguard every couple weeks for active beneficials. The drop this morning wasn't quite as bad, was 6.0 when I went to bed and was 5.4 in the morning.

I'm wondering if I should be using CalMag, I just hate adding more shit though, lol

my plants are looking really happy and green with lots of nice buds everywhere

From your description, i don't feel it would be strictly ph or strictly mg. Forgive me if my numbers aren't but I'm sure they're close enough. You have ~65ppm mg in there and i can't imagine plants are chugging mg when not in light. Honestly, I'm no dwc expert but i think it would be strictly related to dwc because I've given and seen larger ph variations without problems and you're correcting it daily for lights on you said. I also think roots probably have more control of ph in dwc than say my aero(which is more like nft that turns into dwc when roots long enough). Not sure of this yet.

Just so you don't make a mistake grow and bloom have the magnesium, micro has the calcium.

 

[xenon730]

looking it over more it honestly looks more like calcium to me. if your ph is never getting high enough you could be locking it out long enough during the day that it's causing effects. where was this finger taken from? a lighted area? it seems pretty fresh so i'm guessing mid to lower fan in the light constantly? if it's a well lighted leaf it's likely calcium lockout and you should adjust the ph to 6.2 in the morning instead of just 6 just to allow it to get some ca for sure and see if it totally stops. it may already be corrected but you don't need to add any calcium or magnesium or any other nutrient for that matter as 123 is pretty high ppm feed and contains good ppm levels of everything, including 130 of ca and 65 of mg. your food is balanced enough that it's not what you're putting in, so it must be from the ph. i find myself preferring 6.2 or 6.3 even in hydro because the plants drop it so quickly feeding, which in theory will quickly lockout calcium. might be what's going on here.

 

[h4ppyf4rmer]

looking it over more it honestly looks more like calcium to me. if your ph is never getting high enough you could be locking it out long enough during the day that it's causing effects. where was this finger taken from? a lighted area? it seems pretty fresh so i'm guessing mid to lower fan in the light constantly? if it's a well lighted leaf it's likely calcium lockout and you should adjust the ph to 6.2 in the morning instead of just 6 just to allow it to get some ca for sure and see if it totally stops. it may already be corrected but you don't need to add any calcium or magnesium or any other nutrient for that matter as 123 is pretty high ppm feed and contains good ppm levels of everything, including 130 of ca and 65 of mg. your food is balanced enough that it's not what you're putting in, so it must be from the ph. i find myself preferring 6.2 or 6.3 even in hydro because the plants drop it so quickly feeding, which in theory will quickly lockout calcium. might be what's going on here.

you are correct, the few leaves of the one plant that are showing the deficiency are in constant light when the lights are on. I've already taken your advice and have started bumping my pH up to 6.2 in the evening and in the morning.

The other thing is: the bucket that's showing deficiencies is at the end of a three bucket line. I'm wondering if the last bucket is not getting quite enough of what it needs.

 

[xenon730]

you are correct, the few leaves of the one plant that are showing the deficiency are in constant light when the lights are on. I've already taken your advice and have started bumping my pH up to 6.2 in the evening and in the morning.

The other thing is: the bucket that's showing deficiencies is at the end of a three bucket line. I'm wondering if the last bucket is not getting quite enough of what it needs.

Could be, i don't talk about what i don't know so i can't really help you with that particular problem, would just be speculation. I can say though that if you're ever willing to experiment that i think you could potentially get a small, but noticeable, increase in quality by adding some magnesium in late flower. The amount of mg cannabis wants has been greatly understated in my opinion. I've noticed consistent results with getting to 100ppm over the latter half of flower. If you're ever willing to experiment, i recommend giving it a go.

 

[h4ppyf4rmer]

Could be, i don't talk about what i don't know so i can't really help you with that particular problem, would just be speculation. I can say though that if you're ever willing to experiment that i think you could potentially get a small, but noticeable, increase in quality by adding some magnesium in late flower. The amount of mg cannabis wants has been greatly understated in my opinion. I've noticed consistent results with getting to 100ppm over the latter half of flower. If you're ever willing to experiment, i recommend giving it a go.

I love experimenting (within reason), this whole cannabis adventure is just one giant experiment };-)

 

[h4ppyf4rmer]

wasn't happy with the color of the res water so I changed it out and added new nutes and see what happens. currently sitting at 1.2ec 6.0 pH

 

[xenon730]

wasn't happy with the color of the res water so I changed it out and added new nutes and see what happens. currently sitting at 1.2ec 6.0 pH

I always forget to follow your grow closer cause your close to the same day as mine. I'm on w4d3 today. The grows are pretty different though as mine are from seed for speed just to do initial pheno hunting. Anyways, things seem to have stabilized a bit or no?

 

[h4ppyf4rmer]

I always forget to follow your grow closer cause your close to the same day as mine. I'm on w4d3 today. The grows are pretty different though as mine are from seed for speed just to do initial pheno hunting. Anyways, things seem to have stabilized a bit or no?

I just changed the res tonight so we'll see in the morning... I hope things stabilize a little bit.

 

[h4ppyf4rmer]

checked numbers this morning, seems to be much more stable.
sitting at 1.25ec with a pH of 6.2, water temps at 71.

 

[h4ppyf4rmer]

checked numbers again this morning, still stable:
pH - 6.2
water temp - 71
ec - 1.05

I'm thinking the plants are eating seeing that the EC is slowly going down and the pH is stable. I'm wondering if the Beneficials I was adding was causing bad things to happen, I was adding 70ml of Hydroguard every two weeks because of the warm water temps.

 

[h4ppyf4rmer]

still holding strong with no pH issues. I'm pretty confident the res change did the trick. every night I check, the EC is slowly going down without the pH changing.

pH - 6.1
water temp - 73
ec - 1.2

 

[guymandude]

one of my six plants in my RDWC system looks like it's starting to get a magnesium deficiency in my third week of bloom. some of the largest leaves are starting to show spots near the ends.

The reason I believe it's an Mg def is because the pH starts at around 5.8 and by morning it's around 4.6 which makes Mg unavailable according to the charts.

The first problem is trying to figure out why my pH is dropping so drastically over night during lights on time. I'm losing about 1.5 gallons per day of water, so my plants are drinking fine. My EC stays about 1.4 pretty much all the time.

I know it's really common for the pH to drop during bloom but I don't think my last grow dropped quite this much over the course of a day.

if your ph is dropping like that, what are the ppms doing? If they are rising, you need to back off the nutes big time If they are staying the same or dropping a bit, my guess is you have some bacterial growth going on with the roots, rez or tubing or airstones or somewhere. Root rot and funk will cause the ph to drop

 

[h4ppyf4rmer]

if your ph is dropping like that, what are the ppms doing? If they are rising, you need to back off the nutes big time If they are staying the same or dropping a bit, my guess is you have some bacterial growth going on with the roots, rez or tubing or airstones or somewhere. Root rot and funk will cause the ph to drop

It's not dropping at all over the last 4 days ever since I changed out the entire res. I did not add hydroguard this time. I'm very suspicious that the hydroguard had something to do with it. I did check the roots, it all seems fine.

so what was happening was the pH was taking a serious nose dive during lights on. The plants (six) were drinking about 1.5 gallons of water a day. The EC was hanging around 1.4 (TDS of 700) but the water looked relatively clear in the res.

after I changed the res, the pH is steady, the EC is slowly going down each day, and the plants are not drinking as much water.

I have not seen any new leaves that are showing deficiency, so I think I kicked this problem in the nuts... };-)

 

[guymandude]

It's not dropping at all over the last 4 days ever since I changed out the entire res. I did not add hydroguard this time. I'm very suspicious that the hydroguard had something to do with it. I did check the roots, it all seems fine.

so what was happening was the pH was taking a serious nose dive during lights on. The plants (six) were drinking about 1.5 gallons of water a day. The EC was hanging around 1.4 (TDS of 700) but the water looked relatively clear in the res.

after I changed the res, the pH is steady, the EC is slowly going down each day, and the plants are not drinking as much water.

I have not seen any new leaves that are showing deficiency, so I think I kicked this problem in the nuts... };-)

yeah i stopped using any kind of enzyme anything in hydro - sensizyme, hydroguard, whatever.

just change your rez once a week and the crud will stay away

 

[h4ppyf4rmer]

Still think I've got a mg deficiency