New York City Growers - Water Quality

[Irongoat]

Recently on another forum a grower proposed adding a calcium supplement to her potting mix for newly-purchased paphs. I suggested she check her water and fertilizer before doing that. Then I thought, hmm. I really don't know what *my* water provides in the way of minerals, though I know that our water is generally considered low in dissolved minerals.

Do NYC growers supplement calcium for any of their paphs? And how in the heck do you convert mg/L to ppm?

The 2006 water report states an average of 5.4 mg/L of calcium from 334 samples and an average of 1.2mg/L magnesium from 319 samples from Catskill system, and an average pH of 7.3.

John

 

[NYEric]

NYCDEP treats the water before it gets to the city. However, water quality differs depending where in the infrastructure you are. I once saw some water lines that were almost filled close w/ deposits in Bklyn.

 

[Eric Muehlbauer]

Overall, water quality is excellent in NYC. Very soft, pH neutral. I use it straight from the tap, and use MSU pure water formula...I do use a deionizer for the water I add to my reef tanks, but that's because there are trace amounts of orthophosphate in the water...inconsequential for plants, but cumulative in a tank when water is added to replace evaporation....Take care, Eric

 

[Irongoat]

Hi, Eric. Thanks so much. I used to use MSU for pure water too. Even wrote a paper about it for my OS as possibly a good fert. choice for our area. But then one of my brachys (it was either niveum or bellatulum) developed foliage issues. But, I will say I was growing in sphagnum at the time (notorious for holding salts), and I wasn't pre-watering before fertilizing. Live and learn. Maybe I'll try MSU Pure again, exercising a little more care.

Sounds like a good fix to me!

John :>)

 

[Corbin]

Hi, Eric. Thanks so much. I used to use MSU for pure water too. Even wrote a paper about it for my OS as possibly a good fert. choice for our area. But then one of my brachys (it was either niveum or bellatulum) developed foliage issues. But, I will say I was growing in sphagnum at the time (notorious for holding salts), and I wasn't pre-watering before fertilizing. Live and learn. Maybe I'll try MSU Pure again, exercising a little more care.

Sounds like a good fix to me!

John :>)

I don't understand. Why would you water and then fertilize? The fertlizer is mixed in water. If you water first and then fertilize most of the fertilizer just runs out the bottom of the pot because the medium is already soaked with water.

 

[NYEric]

It's a common way not to burn the roots.

 

[Corbin]

It's a common way not to burn the roots.

My practice has been to fertilize, without flushing, two to three times and then flush and not fertilize for one watering. Do you think this is will work?

 

[Irongoat]

Corbin, I used to think that too. But what's happening is that the water from the pre-watering is more or less replaced by the fertilizer solution. And by wetting the roots first, you buffer them against a sudden intake of fertilizer which can cause "burn."

Even some growers of orchids that aren't as notoriously sensitive as paphs (cattleyas, for example, and usually greenhouse growers, I think) will pre-water the day before and feed the next. I suspect so they can use higher concentrations of fertilizer without harming roots. Just a guess.

John

 

[Eric Muehlbauer]

I tghink the rule is that orchids without velamen (paphs and phrags) should be wet already before fertilizing. However, orchids with velamen (the epiphytes) should be dry when fertilized- if the velamen has already absorbed water, it won't be able to absorb any more in fertilizer solution. Take care, Eric

 

[NYEric]

Really? I would think the osmotic action of the cells would flow the solution w/ minerals into the wet cells w/out solution.