Cal-Mag issue?

[Tranquilidade]

Hi,

Help me identify my mistakes. Growing with CANNA Terra Professional Plus. Every time I grow with this medium I start experiencing problems roughly at +/- 4 weeks. New leaves start to yellow with darker veins. For the first weeks, I watered with tap water PH 7.7. After I saw the first signs of yellowing I started to water with adjusted PH 6.4. Also, I watered sometimes too little, sometimes too much, and my LED lights were too high from the start. Right now I solved these problems but my problems don't go away. I have a suspicion that my plants lack magnesium so 1.5 weeks ago started feeding with cal-mag agent. I know there are a lot of problems here but maybe you have some tips on how to stabilize things.

 

[buzzmobile]

Are you using fertilizer? Looks like magnesium along with nitrogen deficiency. Reduce your feed mix pH to 6.0. How much CalMag are you adding?

 

[Tranquilidade]

I'm using cal-mag agent 1ml per 1 litre. I also have Biobizz Fish-Mix and Biobizz Bloom but I haven't used them yet.

 

[HempKat]

Well first off 7.7 is pretty high at that level almost everything is locked out, calcium and magnesium should still be getting thru but they're getting close to the lock out point so good job on bringing the ph down to 6.4 try to keep it there as best you can to avoid future ph issues. Really things don't look all that bad, you show some slight signs of problems. What I see looks mostly like lack of nitrogen and since the plant growth looks reasonably dense for it's height I would try giving them some of that fish mix stuff for now and hopefully the leaves will darken up and look a bit better. Other then that just do your best to be more consistent with the watering and the distance from the light.

 

[TanzanianMagic]

Hi,

Help me identify my mistakes. Growing with CANNA Terra Professional Plus. Every time I grow with this medium I start experiencing problems roughly at +/- 4 weeks. New leaves start to yellow with darker veins. For the first weeks, I watered with tap water PH 7.7. After I saw the first signs of yellowing I started to water with adjusted PH 6.4. Also, I watered sometimes too little, sometimes too much, and my LED lights were too high from the start. Right now I solved these problems but my problems don't go away. I have a suspicion that my plants lack magnesium so 1.5 weeks ago started feeding with cal-mag agent. I know there are a lot of problems here but maybe you have some tips on how to stabilize things.




I see signs that look like overwatering, especially the tips of the leaves in the middle picture. This happens because the roots at the bottom of the pot are in water too long. Beginners should add a drainage layer of perlite or grow rocks to the botton of the pot. I notice that perlite was added to the medium. That's not necessary. As long as you water/feed less often, say only when the top of the medium is dry in the morning, you don't need perlite to increase drainage or airation. And of course perlite also reduces the nutrient content of the mix.

It is also all damage at the tops and growing tips, so it could also be nutrients locked out a higher pH. pH should be about 7 in organic grows.

Canna Terra Pro Plus is excellent medium. I would repot and only give them a high PK late flowering solution plus some epsom salt.

Also, the best way to prevent magnesium issues or even pH issues is to add 1 tablespoon per gallon of magnesium lime to the medium.

Also, with a pH of 7.7, your tapwater may contain chloride or chloramide, which needs time to evaporate - say a day or so. You can tell because both the pH and PPM of the water drop.

 

[Switcher56]

 

[Tranquilidade]

Thanks for all advices. At the bottom of the pot I use grow rocks for drainage. Should I flush all plants or just continue feeding? Also I've sprayed with fish mix solution yesterday to increase the nitrogen level. Don't know if I should continue adding it or nitrogen is not the case here?

 

[LostTribe]

Thanks for all advices. At the bottom of the pot I use grow rocks for drainage. Should I flush all plants or just continue feeding? Also I've sprayed with fish mix solution yesterday to increase the nitrogen level. Don't know if I should continue adding it or nitrogen is not the case here?

I havent used canna terra pro but am well versed in the use of Peat based mixes.

Canna bio terra states that the mix is peat based combined with bark(instead of perlite), enough dolomite lime to keep ph balanced for an entire cycle and enough feed for the first week of growth. If you are going to use biobizz I recommend taking a look on google for the feeding schedule chart. Its also on the biobizz website. Biobizz looks to be atleast a 2 part nutrient line, they call for different ratios of their bio grow and bio bloom depending on the age of the plant, meaning you are missing biogrow. I would also stop spraying fish emulsion on your plants. I never foliar feed anything and you have to do it just as the lights go off and only to the bottom side of the leafs or it will only make matters worse. I dont foliar ever.

Before you do anything, are you doing wet and dry cycles? When growing in any peat based mix it is imperative that you allow the peat to dry between waterings. If you dont it will cause overwatering and can affect N uptake. I dont think you have a PH issue because the dolomite lime is acting as a buffer. However, 7.7ph is high. Start picking up the pot/container that the plant is in and check the weight. It should feel light before you add water. I you can also check that the top 2 inches of the peat is completely dried out. I recommend checking both until you get a better idea of this.

Week Schedule for wet dry cycle for peat
W/D/D/W/D/D/W
Water
Dry

Feeding Schedule for pet for 2 weeks
N/-/-/P/-/-/N
P/-/-/N/-/-/P
Nutrient
Plain Water

If you are already having dry cycles I would begin feeding nutrients at the levels recommended in the feeding chart but since biobiss bloom is only 1-2-2 you may still have a N deficiency. Ideally the biogrow and biobloom would combine to have a higher NPK ratio. I would get a bottle of biogrow and a cheap GH Ph test kit with the drops works perfect, small ph up and down. Optimum Ph levels for peat are between 5.6-6.2 but apply very small amounts of down until you reach yellow/orange and you should be fine. I used to just get it to yellow and did great. I have used pens for many years but the drops do the job just as well and you dont have to clean or calibrate them.

LT

 

[TanzanianMagic]

Canna Terra Pro Plus is made from composted treebark, not a lot of peat. It absorbs quite a bit of water and nutrients, and doesn't need to be watered as often as other media.

The best rule of thumb to use is to water slowly and thoroughly, and then not water again until the top of the soil is no longer moist when the lights go on. This also requires a lower nutrient concentration for the liquid nutrients, because these nutrients will concentrate as the soil dries. So using 25% strength is more than enough.

Also, after repotting, feed with a 200PPM/0.5 EC high P/K nutrient solution and 50PPM/0.1 EC of epsom salt. The P wills stimulate root growth (most importantly), the K will create a strong stem and the Mg in the Epsom Salt creates healthy phototropic leaves.

The best thing to do here is to pot up and give the plants new rootspace to take up nutrients from. And not use perlite (which aerates and drains, however also takes up space in the soil where nutrients should be).

 

[Creeperpark]

The only thing that's wrong with your plant is too high of a pH in the root zone. Your lime green to yellow growing shoots is telling you that the Iron is locked out. If it was Mg deficiency it would be on the older leaves too. When using Tap water and acid together the pH will always swing back up after about 8 hrs when pH-ing your water. You say 6.4 but your plants are saying you are above 7.7 or higher maybe in the 8s in the root zone. When using potting mixes with a lot of wood in them the pH is always higher. Using Tap water you have to stabilize the "hydroxyl content" or (alkalinity) and increase the hydrogen equilibrium before Iron is soluble. One way to fix using tap is to pre-mix acid and water and stablize the pH for 24 hrs before using. If you have a high ppm Tap water, there will be a lot of by-product produced from the acid water mix.

 

[TanzanianMagic]

Check out this image of a zinc deficiency. The ribbing effect and the tips of the leaves look very similar.

https://groadvisorworldwide.com/wp-c...QS_Blog-10.png
https://groadvisorworldwide.com/cann...-deficiencies/

The reason for zinc lockout is the same for iron - a high pH.

To remedy a high pH of the tapwater:

- Let the water sit next to the plants at room temperature for at least a day, and see if the pH and EC drop. At least the chloride, which is alkaline, will evaporate.
- Put a teaspoon of magnesium lime in a quart of RO water, let it sit for a day and then mix the clean runoff with 3 quarts of RO water to the gallon. This reduces hardness, which means you have to use a lot less acid to get the pH to 7, if any is needed. The magnesium lime takes care of the magnesium deficiency that goes wtih R/O water. (Corrected.)

I don't have good personal experiences with using acid on soil. It always seems to create complications. I wouldn't grow a coco grow without it and the same for hydro if I did that. Just not soil.

 

[Creeperpark]

In regards to your message. You just have to keep adding acid until you reach equilibrium and it becomes stable. It can take up to 48 hrs on some waters. Tap water and the problem with using all that acid is there is a by-product that appears and the ppm rise. That by-product will accumulate and will block receptor sites in the root zone and cause leaf bronzing later in flowering. Tap water is a problem if you live in a large populated city because of the water treatment. I never use tap on any plant that's in containers. You can mix 60/40 tap to RO and stabilize the pH easier.

 

[Chevy cHaze]

I'm using the same medium but bio canna terra nutes which you don't even have to ph.
Works a treat but I had to topdress and water in some dolomite lime in week4 under high powered LEDs. I'm also using blumats and do additional nute feeds twice a week, so the medium never dries out and the plants seem to love it...
Just my 5cts
Good luck
CC

 

[TanzanianMagic]

Hi,

Help me identify my mistakes. Growing with CANNA Terra Professional Plus. Every time I grow with this medium I start experiencing problems roughly at +/- 4 weeks. New leaves start to yellow with darker veins. For the first weeks, I watered with tap water PH 7.7. After I saw the first signs of yellowing I started to water with adjusted PH 6.4. Also, I watered sometimes too little, sometimes too much, and my LED lights were too high from the start. Right now I solved these problems but my problems don't go away. I have a suspicion that my plants lack magnesium so 1.5 weeks ago started feeding with cal-mag agent. I know there are a lot of problems here but maybe you have some tips on how to stabilize things.

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The tops are mainly affected, which points to a high pH.

I think there is chlorene in the tapwater, and that it both causes a high pH in the water, and may be building up in the medium over time.

I would just let the water stand near the plants for a day or two, and measure the pH and EC. If they have gone down, the chlorene has evaporated.

Also, Canna Terra Pro Plus doesn't need perlite.

And make sure the pots are of adequate size - 1 gallon per 1 foot of expected growth at a minimum - to avoid nutrient deficiency issues.