TDS Totally Confused

[Mistakes R Crucial]

Hi all,

I am totally confused!

My tap water has a KH of 1 straight out of the tap so I think it is categorised as very soft. Now that I have my first two pairs I thought it important to get to grips with TDS and make sure all is OK for successful spawns. This is where the confusion starts.

I don't have a TDS meter but I do have an EC meter I use for my hydroponics. I looked up conversion rates and apparently there are 3, anywhere from 500-700m/s depending on the manufacturer. I took the middle road and therefore 600m/s = 1 EC. My tap water has an EC of .4 so based on the conversion it has a TDS of 256.

After reading many posts it would appear (I would love to be wrong here) that a TDS of 256 is very much on the high side to successfully breed Discus.

I'm confused because I thought that the hardness of water was dictated by the amount of salts/minerals in the water and as my hardness is very low I thought the TDS/EC would also be very low, in hydroponic terms it is but in Discus terms maybe not.

Would appreciate some clarification here, thank you.

Nigel

[Carol_Roberts]

Apples and oranges. KH measures disolved carbonates (minerals) tds measures everything disolved in the water.

You could have pure RO water . . . add a bunch of salt and tds would go through the roof, but KH (and GH) would not budge

[Mistakes R Crucial]

Thanks Carol. Do I take it then that if my KH/GH is pretty low (KH 1) the water should still be OK for my pairs even though they have a TDS of 256?

NB

[Carol_Roberts]

I think so.