Flush with tap water
 

Hi I transferred all of my orchids over to Simi hydro last year and they seem to be doing pretty well including this coelogyne cristata that has never flowered before.all my water comes from collected rainwater and I was just wondering what the thoughts are about if I flush the pots out with tap water which is a little bit hard and then top up until the water flows out the bottom of the pots with the rainwater. at the moment I am filling the pots to the top with the rainwater and obviously this uses up a lot especially on the bigger pots. However I wondered if I fill up each pot with tap water and in run through a smaller amount of rainwater would that be harmful at all?

If you are trying to flush nutrient salts out of your medium I would be careful using tap water. It would be best to use distilled, or RO water.

Tap water is usually a lot higher in PPM than you would think.

Give me a number that explains “a little bit hard”.

It might be perfectly fine.

I just put my postcode in the water companies web page and it just came back saying very hard water but didn't give me any figures

Yes, if you run the rain through after the tap water, it will remove most of the minerals. From the logarithmic function a volume of rain 3 times the volume of tap water remaining in the reservoir and adherent to the LECA will remove 97% of the minerals.

You can pick up the pot and cover the holes with your thumb or the base of your thumb to reduce the amount of water needed to fill the pot.

Thank you. Perhaps I will try it on a few and see if it makes any difference. Dont fancy holding my fingers over the holes of 150 pots.:)

I can only manage ten at a time.

Can you share the math on that, please?

Does it take into account dissolution dynamics?

Logarithmic decay of flushing, rinsing.

:rofl: