Calcium deficiency in tomatoes

[Kangaroo1943]

I wonder if any one can help me , I have detected in my ebb and flow system, some blossom end rot on a couple of my tomatoes , and I understand that calcium is deficient.
As I have a 200 litre reservoir, I purchased some calcium nitrate granules to mix into a base nutrient solution.
I have 1 kg pack of 19% calcium, 15% nitrogen .
Does any body know the dilution rate I should use to 1 litre, as my hydroponic supplier did not know.
To use a pre packaged Calcium/Magnesium liquid nutrient the dilution says up to 4ml per litre which x 200 litres = 800mls and that is why I went for the granule concentrate of calcium nitrate.
Any help would be greatly appreciated.

[tomc]

Um, actually BER (blossom end rot) is a function of calcium uptake. Irregular watering and cold temperature cause this.

You can use calcium by the shovel-full thats not gonna fix what ails your tomatoes.

[Kangaroo1943]

I live in the sub tropics where it never gets below 15C in in the middel of winter, and I have a timer that comes on at regular intervals so it is not temperature or irregular watering. I have been using powdered A and B formulation for years and never ever had blossom end rot.

[pepperhead212]

While I have never grown tomatoes in hydroponics, I'm sure your problem is not irregular watering!

Are you having this problem with all of your tomatoes, or just certain varieties? I ask because I have had problems with BER with various varieties, one of which (Salsa) I eventually pulled from the ground, as every one of them had BER, while others, in the same soil, had no problems. And many get it in the first half dozen or so, then not another the entire season.

I can't tell you how much to add, only that it was listed as 60-0-0 as a fertilizer, so you can't add too much, or you'll upset the balance of the nutrients.

[imafan26]

Since this is a hydroponic system uneven watering is probably not the cause but an imbalance in the nutrient solution.

150 ppm Ca is recommended for all growth stages in tomatoes. The final amount required may need to take into account what is in your water source.
This may help. You can check to see what concentrations you have in your nutrient solution. I probably won't help the tomatoes with BER now but may be able to improve things for future ones.

https://edis.ifas.ufl.edu/cv216

[Kangaroo1943]

Thanks everyone for your comments, as mentioned I have never had blossom end rot before, and the only reason I can put down is my nutrient mix A and B powdered , that I had pre mixed in 20 litre containers and was 1 year old ,plus it may not have been mixed well as I noticed towards the end one of them looked a little second hand.
However in the meantime I have added a very small amount of Calcium nitrate to a new lot of A and B concentrate hydroponic mix and everything is looking up and healthier.

Ps I forgot the mention that I only had one tomato with BER in my ebb and flow system, and 3 tomatoes in my DWC tray.
So it was not a lot of problems but my plants were not looking 100% so I took the action that I have mentioned.