Will plant food increase hardness?

I have what would be deemed "very soft" water at home (average of
13ppm). I always use the "blue crystals" to increase hardness when
setting up a new tank, or doing water changes.

I always use the recommended amount.

I had my water tested at my LFS last weekend, and the hardness was HARD
(390ppm).

I had added some plant food in the week prior to the test. Am I correct
in assuming that all the goodies in the plant food may have sent my
hardness through the roof?

.

Relevant Pages

  • Re: Will plant food increase hardness?
    ... I always use the "blue crystals" to increase hardness when setting up a new tank, or doing water changes. ... I had added some plant food in the week prior to the test. ...
    (rec.aquaria.freshwater.misc)
  • Re: Biowheel 330 enough for 55 gal?
    ... I had almost the same advise from my LFS. ... I did my weekly 30% water changes. ... >>> heard him comment to another employee about water changes solving ... >did partial water changes. ...
    (rec.aquaria.freshwater.misc)
  • Re: salt
    ... So you should take it slow on adding critters so that you don't have to spend so much money on water changes. ... The LFS said the RO is more than adequate. ... The owner of the store said that the canister in actually the main problem (gee, you think they would of said so when I bought it). ... I'm taking out the Bio Balls and I'll keep a close eye on it. ...
    (rec.aquaria.marine.reefs)