Question concerning ppm with new plants in tank !!

[hironobu]

I have recently bought a "Echinodorus palaefolius var. latifolius" plant from the sword family. I placed it in my 30G tank as is without any additives. A day later I noticed the ppm shot up to around 500 and it was around 170s. I have four discus in the tank and they seem to be alright but I was very concerned for their well being and have removed the plant and did a 60% WC to lower the ppm down to 200. I continue to monitor the health of my fish and will do another 50% WC tomorrow. But my question is why does the ppm rise like that with the presence of a plant? Is it normal? How much harm will it do to the fish? Thank you for all your help in advance.

[Moon]

The introduction of a plant should not have any impact on your water hardness. If the plant is in a pot the substrate might have some effect. Your discus can handle hard water as long as it does not vary suddenly. The most important thing for discus is stable water conditions. My discus are growing out in hard well water TDS of 350 and Ph 8.5. You need low TDS for breeding discus.

[GrillMaster]

Did it come potted? If it did, an you just put the pot in the tank, the rockwool could be affecting the hardness...