Bio G Power - Calcium MG

A concentrated calcium and magnesium supplement in one bottle, for soft tap water and reverse osmosis water. 1 ml per litre, right through the cycle.

Why these two are always sold together

You can buy calcium and magnesium separately. Yet most of this shelf is bottles with both in them, and there are two reasons for that which rarely get explained.

The first is that they compete for the same place. Calcium and magnesium are both taken up as divalent ions and crowd each other out at the root. Feed too much calcium and you watch a magnesium deficiency appear while there is plenty of magnesium in the tank. Feed too much magnesium and exactly the reverse happens. So what matters is not the amount of each but the ratio between them, and in a blend that ratio has already been fixed for you.

The second reason is chemical and more practical than it sounds. Magnesium fertilisers are often sulphates and calcium fertilisers often nitrates. Bring a sulphate and a calcium salt together undiluted and you get calcium sulphate, better known as gypsum, which barely dissolves. It drops out as a white sludge in your measuring jug or, worse, in your lines.

So anyone buying the two separately has to keep them apart until both are dissolved in a decent volume of water. In a blend the manufacturer has already solved that by matching the forms to each other.

When you need it

Soft tap water and water from a reverse osmosis unit are naturally short of calcium and magnesium. Your base feed quietly assumes there is something in your water, and on RO water that assumption does not hold.

On hard tap water the story is different and you often need little or none. So look at your water before making this a standing part of your schedule.

Dosing

Mix 1 ml per litre of water, which is 1 in 1000, and adjust it against the starting value of your RO or soft water. Feed continuously through the whole life cycle, in both vegetative growth and flowering.

Add it to the clean water and mix it through before the base nutrients go in. Store the bottle dark and frost-free, out of direct sunlight.

Available sizes

Technical Specifications:

• Type: concentrated liquid calcium and magnesium supplement
• Manufacturer: Bio G Power
• Dose: 1 ml per litre of water (1 in 1000), adjusted to your starting water
• Period: the whole life cycle, vegetative and flowering
• Intended for: soft tap water and reverse osmosis water
• Substrate: soil, coco and hydroponic systems
• Adding: to the clean water, before the base nutrients
• Storage: dark, frost-free and out of direct sunlight

Frequently asked questions

Why are calcium and magnesium in one bottle?
Because they compete for uptake, so the ratio between them matters more than the amount of each. In a blend that ratio is already fixed.

Can I not buy them separately and mix my own?
You can, but keep them apart until both are dissolved in plenty of water. A sulphate and a calcium salt meeting undiluted form gypsum, which precipitates.

Can too much calcium give me a magnesium deficiency?
It can. The two crowd each other out at the root, so an excess of one leaves the other behind even though it is in the tank.

Do I need this on hard tap water?
Often barely. It is meant for soft and RO water, where these elements are naturally absent.

When do I add it?
Into the clean water, mix through, and only then the base nutrients.