Fertilizer choices and water type - Orchid Board

Michelle15 · #1 01-26-2016, 10:59 PM

I have been using Green Jungle Orchid Fertilizer in distilled water for the past several years and have had decent results but some of my orchids have had underwhelming blooms. I just ordered Dyna-gro for orchids 7-8-6 to try and was wondering is this made to be used with tap water or distilled? I have pretty hard tap water here. Getting too many orchids to use distilled all the time. During warmer months I use rain water when I can.

Ray · #2 01-27-2016, 10:04 AM

The Dyna-Gro Orchid Pro formula may be used in pure water, but be sure to check the pH. Most fertilizers are designed for use in tap water containing minerals, as they buffer the pH, preventing wild swings upon the addition of the fertilizer. Once you remove those minerals, all bets are off.

The fertilizer formula itself probably has little-, to nothing to do with your blooming issues. How often you feed, and at what concentration can also play a role, as do the light levels, temperatures, and your watering frequency. Share more info, and we can be of more help.

Using pure water on orchids is a real "plus", but buying it can be expensive. If you have a large collection, a standard reverse osmosis system is a worthwhile investment. If your collection isn't huge, one of my counter-top systems will give you all the RO water you need for a smaller amount of money. Based just upon the purchase price and output before any cartridges need to be replaced, the cost is around $0.05/gallon; longer-term, it's even less.

Subrosa · #3 01-27-2016, 10:56 AM

If you live in your own house, a rain barrel is easily plumbed into your downspouts. Used drums can be had really cheap, and even free sometimes. You do need to know what was previously in the barrel! Food ingredients are always good, and many other chemicals don't pose a threat to you or your plants. I get them from a fellow member of my local aquarium club. They're from where he works, and contain a 20% solution of ethanol in water. After they're empty they're stacked away for recycling in one way or another

A couple rinses and they're clean enough to drink out of. Cleaner, but not as much fun

Michelle15 · #4 01-27-2016, 04:10 PM

What pH should I be looking for with the fertilizer added?

Ray · #5 01-27-2016, 06:07 PM

Personally, I shoot for 5.5-6.5, but what's actually more important is the pH in the root zone.

Water and feed your plants normally, so the potting medium is saturated. Wait about an hour, and dribble a small amount of that same fertilizer solution through the medium, collecting the drainage. The pH of THAT should be in that preferred range, or even a little bit outside of that.

Michelle15 · #6 01-27-2016, 08:40 PM

Thank you I will check pH with my current fertilizer and with the new one, see what I get.

Michelle15 · #7 02-09-2016, 11:40 AM

Quote:

Originally Posted by Ray

Personally, I shoot for 5.5-6.5, but what's actually more important is the pH in the root zone.

Water and feed your plants normally, so the potting medium is saturated. Wait about an hour, and dribble a small amount of that same fertilizer solution through the medium, collecting the drainage. The pH of THAT should be in that preferred range, or even a little bit outside of that.

So I did this with a few of my plants today using my current fertilizer (Green Jungle) and distilled water. Before using the pH was about 5.5. When I collected the run off 1 hour after initially watering, I got between 4.3 and 5.1. Is this too low? I made sure the meter was calibrated and it was fine. 2 of these orchids are in spike (phals) and one is growing well but no spikes yet (Oncidium) so they seem to be doing fine. I haven't tried the Dyna-grow yet, will check that the next time I have some due for fertilizing.

Ray · #8 02-09-2016, 01:59 PM

I would view that as being too low, but not to a major degree.

terryros · #9 02-09-2016, 09:19 PM

I confirm that the pH you measured with Green Jungle and RO/distilled water is about right. What we get after an hour with the pour through method is then dependent on the media that we use. When I used to use pure sphagnum moss with either Green Jungle or K-lite, my pour-through pH was as low or lower than you are measuring.

When I switched to a combination of GrowStones and milled sphagnum moss, my pour through pH rose to about the mid 7s because of the GrowStone effect. I now use some lemon juice in the fertilizer solution which helps several things, including lowering the pour through pH into the 6s.

To raise the pour-through pH when I was using sphagnum moss alone I needed to add something and used horticultural lime or crushed oyster shell. There are several other options but it is hard to be precise with any of these.

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Tone · #10 02-13-2016, 06:06 PM

I've had great luck with Miracle Grow - Orchid (course mix). It's bark pieces no longer than an inch long. It drains perfectly, but requires a bit more attention as it tends to dry out very quickly. I water my plants about 3-4 times per week to keep the bark moist.

As for water, i'm not so picky, but i often like to use the remainder of a water bottle if i haven't finished it, distilled water, and even carbonated water from my sodastream machine (i realize the CO2 in the water probably does nothing for the plant in reality, but the concept seems sound enough, lol).