greenhouse grade calcium nitrate.
a lot of people use cal-mag as a supplement.
greystoke has given instructions previously about how to extract calcium from seashells or eggshells (you'll have to do a search for that)
Some people suggest too high a nute temperature will keep the calcium from transporting(I haven't experienced that)

How does this help?

Hmmm.. . well lets see;
I suggested three sources of additional calcium and I recommended he look into issues of excessive temperature.

B.E.R is (in most cases) due to some combination of too vigourous (vegetative) growth, irregular or insufficient irrigation, heat and actually immobility of the Element Ca that can't follow the growth and plan't's need during blooming and/or fruiting stage. Supplementing with any Ca source will not help if plants are already affected by B.E.R. Even foliar spray may not be effective enough or the applied Ca may be too slow to reach fruits.

Adding calcium nitrate to the nutrients would induce even more vigorous and vegetative growth, because of its high content in Nitrogen. And that would make things rather worse than help anything. In fact, one part of B.E.R prevention is to lower Nitrogen content of your formula(s) already from start.

If air temperatures are high anyway, cooling down nutrient temperatures may not help or be ineffective. It's best to cool down both simultaneously. Pick all affected tomatoes a.s.a.p, shade and ventilate the plants and keep nutrient temps in limits. Assure regular and sufficient flow of nutrients. Lower Nitrogen proportion, with next growth even earlier. Any Ca additives may be too slow, the best shot (if there is any) would be foliar spray with CaCl or a mix of CaCl with some Calcium Nitrate based solution or other appropriate Ca sources.

More: some "bloom" formula with too high Phosphorus content may precipitate calcium and thus make it partially unavailable, not actually induce but possibly aggravate BER.

Grizz, I think she means how does calcium help.

Calcium is important in cell growth. It is most evident with blossom end rot because the blossom end of the tomato isn't getting enough calcium. It looks like it's rotten and eventually will. Some varieties are definitely more prone to it. Romas, particularly. Calcium is one of the immobile nutrients, so the plant doesn't take reserves from the leaves like it will with, say, nitrogen.

Temperature issues have to do with oxygenation. High temps mean lower oxygen content. Doesn't matter if you aerate if the water doesn't hold it. And it's made worse if your air is too hot from exposed long airlines (outside) or a big air pump that runs hot. This causes problems with calcium absorption. I have a feeling that this is more likely to be the case with systems where roots dangle in water like DWC, WaterFarm, or the like. I've experienced it in the WaterFarm types, but that was also with Romas.

Often, it doesn't matter how much calcium you add. The problem is supposedly more likely to be in the plants ability to transport the calcium. Not saying you don't want to supplement. Just saying that supplementing without changing potential other causes will be a huge waste of money with disappointing results. I would still supplement as the plant does use more calcium in fruiting. I'm highly interested in greystoke's suggestion that grizzman alluded to.

The water temperature is 54° and the greenhouse fan thermostat is set on 75°. I'm growing cool weather crops in the same greenhouse so I keep it low. I noticed the BER on the largest fruit of a Beaver Lodge (Indeterminate) variety.

Could the cool temps be a contributor?

Mark

Ah. Thanks, Joe. It seemed an uncharacteristic response. I hadn't considered people not knowing what BER was.

Mark, I don't know of-, nor see any indication that 75° F could be a contributor for B.E.R. as this is around ideal. But how comes that nutrient temps are that low? If my converter is right, 54 F are only 12.22° Celsius!

Obviously with ideal or lower temperatures, I wouldn't look further into classical B.E.R. causes related to HEAT and those I have listed. It might indeed be due to some direct Ca lack or lockout then. When I mentioned Ca precipitation due to high Phosphorus content it wasn't just my own conclusion or a "adventurous speculation" - and in your case I would investigate your nutrient composition and balance.

There are some roles for a balanced an successful tomato formula, which I posted numerous times here. If using some commercial formula with growing some "random but forgiving" variety instead, one may be lucky and the combination of base water and nutrient composition may be just fine or good enough - but one may as well run into deficiencies or imbalances of the sort.

"Calcium is important in cell growth. It is most evident with blossom end rot because the blossom end of the tomato isn't getting enough calcium. It looks like it's rotten and eventually will. Some varieties are definitely more prone to it. Romas, particularly. Calcium is one of the immobile nutrients, so the plant doesn't take reserves from the leaves like it will with, say, nitrogen. "

Do you know of any signs to look for of too much calcium? I add it to my tomato's, but don't really want to be making it too strong. I generally add about 5mL per gallon to flora series nutrients.

Lucas,

The nutrient temps are cold because of my greenhouse design and my climate and the fact that no sun hits the bucket the tom is in. Winter nighttime temps, in the GH stay similar to what they are now because of the water thermal storage and the angle of the sun striking them. I live at 7400' in SW Colorado where days in May and June can reach 80+ and the same night can still dip to below freezing. I don't heat the GH, thus the large temp swings. (a low of 47-48 at night) Could that contribute?

The solution I use has 2% Ca so it must be uptake or something else. Ph is around 6. Maybe I'm overreacting, because it's on just one fruit so far.

Mark

It is important here to note that calcium uptake is not directly proportional to Ca concentration in the nutrient solution since high concentrations of an ion may lead to reduced uptake. Potassium is also antagonic with calcium and high levels of this nutrient may hinder calcium absoprtion to a large extent. A ratio of K/Ca of about 2:1 has found to be optimal on some studies.

However in your case it may be due to the development of strong temperature differences. It is very common for blossom end rot to develop under these conditions since irregular water uptake is present. Temperature differences are the most likely the cause of this problem. Improving insulation or providing some heat at night may eliminate the problem. Also using less concentrated nutrient solutions may also help as a lower EC will help the plants deal with the temperature swings.

I hope this helps :o) !

Daniel

Here is a link that might be useful: Everything hydroponics

You may very well be right Daniel, although the GH is well insulated. (R-10 foundation foam, R-19 walls and R-30 non-glazed ceiling area). In early February, when outside temps were 8°-10°, the inside lows were 45-46° with no heat importation. It is the angle of the sun now- it barely strikes the black water filled barrels. In winter, there is more direct heating of that water thermal mass. My hydro buckets sit on those barrels and are shaded by other containers and lots of foliage.

BTW, outside temp this morning is 31°. Inside GH is 49°. Predicted high of 75°. A very comfortable but challenging climate here.

Those toms did experience rapid growth, though. From 1' to 4' tall in maybe 3 or so weeks.

Mark

@Luc - You mention having written numerous posts on tomato formulas. If you bookmark one post and just link to it, you could put it in the "helpful" link at the bottom. That would help anyone new to the forum find it easily without a search.

Let's call it "transpiration stress" due to quite extreme temperature changes that results in problems with already slow calcium fluctuations. Nutrient balance may in fact only play a minor role in that/this case.

Not sure about Daniel's recommendation of lowering the nutrient concentration, as this case is a bit special. If you go by the book, with lower temperatures and because of less transpiration - higher nutrient concentrations are actually recommended. I'd rather (preferably) try to "equalise" the temperature changes somehow.

PS: you haven't mentioned your EC, or have I missed it... and you say 2% of calcium but that is unfortunately vague, as it could be expressed in CaO or in elemental Ca. As a "stand alone" info, 2% doesn't really say much. As Daniel pointed out the ratio of 1:2 to K, you would also have to consider if it is K and not KO2 you'd compare with Ca. A bit complicated I know, but that's the drill as you want to find out real figures before detecting a disproportion. ;-)

@Joe, well I am quite productive (some may call it rather hyperactive and intrusive ;-) but as you can't have it all, I am extremely disorganised and would have to search for them one by one like anyone else...

Today, I was told to try hydrated lime. Anyone use this?

Mark

I use it for my corn tortillas ;-)

Lucas,

Today I took your suggestion and sprinkled hydrated lime (instead of salsa) on my corn tortillas. Delicious! Everyone should try it. And I've experienced no post meal heartburn, to boot.

Cheers,
Mark

That's funny! LOL
I firstly came to experience the actually funny taste of hydrated lime in original tortillas back in 1980/81 during my stay in Mexico and Guatemala. I guess that many "outsiders" ignore the fact that the "soapy" taste of original corn tortillas comes from in fact considerable quantities of lime that is mixed to the corn flower, actually as a natural conservation agent.;-)

But back to topic: when reading through Daniel Fernandez's ebook - actually when going through the components he uses with the spreadsheet, I came across another component that provides extra Ca. It's calcium dihydrogen phosphate. If all needed phosphorus is provided by calcium dihydrogen phosphate, instead of mono-potassium phosphate, you will in fact have an extra amount of Ca in your formula. Although the amount of phosphorus is supposed to be low, at least it will provide some more Ca.

Warning: do NOT spread any calcium dihydrogen phosphate over your tortillas now!!! LOL, it will not only induce post meal heartburn (instead)... but most probably a more extended set of toxicity symptoms!

Here is a link that might be useful: international hydroponic forum

I was just rereading this thread. I guess I missed the section where you (Mark) replied on your temps. You mentioned 54 degrees. I'm almost positive that is too low for optimum calcium uptake. I can't remember the exact minimum, but I recall ideal starting around 10 degrees higher. You might want to look that up for more info, but I've little doubt your low temps are a contributor. I know that soil temps that low can contribute to BER and poor growth in general in a ground garden.

We had this problem big time, along with blossom drop, last year. We added extra calcium this year and also let up on the nitrogen. So far, we haven't had the blossom drop, just a little of the blossom end rot. We got hot this hear very early and this could be our problem.

Here is a link that might be useful: Tomato Blossom End Rot and Blossom Drop

The Blossom end rot is starting your tomato's too early and flower drop is from too high temps and not enough moisture.

Here's a couple of link you may find useful

(Growing tomato's hydroponically) http://ag.arizona.edu/hydroponictomatoes/overview.htm
(Common tomato diseases and problems) http://home.earthlink.net/~shelly.johnson/tomato.html

Here is a link that might be useful: Common tomato diseases and problems