Acceptable PPM of water for Semi hydro?

[stripyorchids]

I am interested in trying semi hydro and wanted to ask what TDS is the upper acceptable level for s/h?
My tap water is 86ppm and I use this to water my orchids in bark medium but am fairly sure that is too high for s/h.

I don't have an RO system, I don't have enough orchids for it to be worth it. I can buy fairly cheap containers of deionised water (0ppm) from my local Tesco just to try it out but that's not a sustainable solution long term. I do want to buy a water filter but I am not sure how effective those are. I did see an article that suggested that filters halve the TDS, if that is the case would ~43ppm be usable or is that still too high? What do you suggest?

Thanks in advance!

[WaterWitchin]

What type of orchid? I don't measure TDS because the orchids are expected to adapt. And they do. You just have to flush more. Last city water report TDS was 320.

I ask what type of orchid, because that doesn't work well for some. My phrags and paphs instantly come to mind. For them, to grow well they need a better water (R/O, rain water, etc.) Onc, Catts, phals, etc, seem to do fine.

[Ray]

The water requirements for semi-hydroponics is no different from that for traditional culture.

The purer, the better in all cases.

[stripyorchids]

Originally Posted by WaterWitchin

What type of orchid? I don't measure TDS because the orchids are expected to adapt. And they do. You just have to flush more. Last city water report TDS was 320.

I ask what type of orchid, because that doesn't work well for some. My phrags and paphs instantly come to mind. For them, to grow well they need a better water (R/O, rain water, etc.) Onc, Catts, phals, etc, seem to do fine.

Thanks for the response, I currently only have phals and an oncidium because anything else is hard to come by in shops and garden centres in the UK but I do want to order some orchids from online, cattleyas and paphs are the first on the wishlist so I shall have to figure something out regarding water! Ideally I need to give them all the same water to avoid having to mix up fertiliser in separate containers but since RO is out of the question for the moment and I don't know how to collect rainwater effectively (I don't have a drainage pipe I can place something under and just leaving a bucket out and waiting for the heavens to open is painfully slow) thus I shall have to start with tap water and use deionised once I get my paphs

[Ray]

I invented S/H culture for orchids and arguably have more experience growing them that way than anyone.

Please read what I said above.

You're overthinking this.