adding lemon juice to watering

[oscar freak]

one of the guys operating a stall at the local orchid show said to add some lemon juice to the water when watering as an acidic ph boosts nutrient absorption,how true is this?

[silken]

There is some truth to it. If the pH is too high or too low, it prevents nutrient uptake. I have started using a pH down product because out tap water is terribly high at 8.5 or 9. Remember plant food lowers it too, so you should really test yours and see if it need to be lowered before using it.

[cbuchman]

Get a Ph Meter before you start adjusting your Water.

[oscar freak]

i test my water for the fish tanks so i know the ph is high.i use a ph buffer for them but was hesitant to use that on the orchids.

[silken]

It should be OK then.

[Subrosa]

Originally Posted by cbuchman

Get a Ph Meter before you start adjusting your Water.

100% right. You need to fully understand what your plants need and what you have and want waterwise before you know whether anything needs changing. Then and only then determine what changes need to be made. Lowering pH will almost certainly increase the availability of some nutrients. It will almost just as certainly decrease the availability of others. This is why extremes of pH are rarely good for plants, even those we think of as acid loving.

[Orchid Whisperer]

Getting a pH meter is good, but if the meter can't be calibrated to standard pH buffers, or if it does not temperature-compensate, you may be better off using pH tests strips, or a pH test kit.

For most purposes, knowing the pH to the nearest unit (scale of 1 to 14) is sufficient. You can get enough test strips for 100 tests for under $17 U.S.

Some nutrients are more available to plants at moderately low pH (roughly 5.5 - 6.5, examples iron, copper, phosphorus) while other are more available at roughly neutral (pH 6.5 - 7.5; examples molybdenum, calcium, potassium) or slightly higher pH. Adding fertilizer to your water may modify the pH, and the pH can change a little or a lot, depending on what is already dissolved in the water (the ability of a water to "neutralize" acidity, due to is called alkalinity alkalinity).

Without going into a lot of detail, it is OK for your water's PH to fluctuate a little, within a range. I would aim for pH mostly between 5.5 to 7.5, but don't lose sleep if pH is slightly higher or lower than this occasionally, as plants can absorb some nutrients even at pH slightly outside the preferred range.

[Ray]

All of the information given is correct - to an extent.

OW is dead on. Yes, plants have preferred pH ranges, but meandering outside of that is not a death knell.

The "pH versus nutrient availability" graph we've all seen is the result of testing of a single fertilizer formula in a single soil sample. Soils have orders of magnitude more cationic exchange capacity (CEC) than do any orchid medium, and it is that CEC that determines whether it's available to the plant or trapped in the substrate.

Unless you go way to the extremes in pH, the structure of the ionic species to be absorbed does not really change with pH, and neither does the plants' ability to take it up. In essence, "if it's in solution, the plant is able to take it up".

[astrid]

Originally Posted by oscar freak

i test my water for the fish tanks so i know the ph is high.i use a ph buffer for them but was hesitant to use that on the orchids.

I don't think that using a buffer system for orchids would be good for orchids.
The buffer system involves the base and conjugate acid (or the other way depending on the system) and that involves a lot more salts being in the solution than normal.

The extra salts will give up protons or take on protons (extra hydrogen salts) to keep the pH balanced, but for the plants this means an overall higher concentration of salts in the system.

Or at least that's my understanding.

So no buffers for orchids.
I say this as a chemist undergrad with junior standing and lab experience, so take it with an ion of salt.

[oscar freak]

Originally Posted by astrid

I don't think that using a buffer system for orchids would be good for orchids.
The buffer system involves the base and conjugate acid (or the other way depending on the system) and that involves a lot more salts being in the solution than normal.

The extra salts will give up protons or take on protons (extra hydrogen salts) to keep the pH balanced, but for the plants this means an overall higher concentration of salts in the system.

Or at least that's my understanding.

So no buffers for orchids.
I say this as a chemist undergrad with junior standing and lab experience, so take it with an ion of salt.

that was my understanding as well lol with salt and some tequila

---------- Post added at 01:20 AM ---------- Previous post was at 01:18 AM ----------

how much lemon juice would we be talking about exactly and is there any other organic method,like tea bags(which i use for my azaleas).