tap water ppm question

[af4444]

tested some fresh tap water straight out of the faucet, ppm = 55. tried testing some tap water that has been sitting in a plastic bin for about 3 days, ppm = 75. does this make sense? shouldn't the ppm be going DOWN as chlorine and other chemicals evaporate from the water? also, considering it's city water, shouldn't the ppm be higher? read a lot of threads with people saying their water was a few hundred ppm straight out of the tap.

will calmag plus be needed??

thanks!

af4444 Reviewed by af4444 on 08-28-2009. tap water ppm question tested some fresh tap water straight out of the faucet, ppm = 55. tried testing some tap water that has been sitting in a plastic bin for about 3 days, ppm = 75. does this make sense? shouldn't the ppm be going DOWN as chlorine and other chemicals evaporate from the water? also, considering it's city water, shouldn't the ppm be higher? read a lot of threads with people saying their water was a few hundred ppm straight out of the tap. will calmag plus be needed?? thanks! Rating: 5

[smello]

I would like to see this one answered

[smello]

have same #s

[jonnychimpo]

well first off when you let tap water sit out its only to evap chemicals that are not wanted in your plants. as far as your ppm it will change when you add your nutrients after you add your nutes then you will want to adjust the ppm, and the ph balance otherwise your just gonna screw yourself and your plantsimp:

[LOC NAR on probation]

Very strange that it goes up sitting out. it could of gone up because the water evaprated faster than the chemicals.

That is very low at 55 ppm's. You should add calmag plus to about 250 ppm's.

what are you testing the ppm's with ?

[af4444]

have a "primo" by hanna meter.

[LOC NAR on probation]

That's a good one. is it calibrated ? not that it would change anything.

I stand by what I said.

[bitemybud]

Yes. You should add Cal-Mag

[Rubberbubbler]

I to have noticed that when you let tap water out the ppm climbs. also which is better cal-meg or magic-cal. I use ro water it comes out at 0 ppm and I use magic-cal but the plants act like they don't get enough I use the least amount that it says on the bottle should I go full strength sense my watter is at 0 ppm

[LOC NAR on probation]

If it is like cal mag plus or cal max. Then I would go to 250 ppm's. If you don't have a meter don't raise it all at once. Do it in 2 or 3 step, no sense in using too much.