Hi all. I'm not sure if I posted this or not, but I've been concerned about the free (toxic)
ammonia level in a tank I'm cycling (with fish). In cases where you've added AmmoLock or one of the other additives that detoxifies ammonia, the ammonia may be tied up and non-toxic, but will still show up in the
API solution test. This can get pretty confusing. One of the 2 solutions in the API test raises the
pH in the test tube to 12, which releases any the ammonia that has been detoxified by AmmoLock & similar treatments. So, if you've used one of these things the API test doesn't tell you the whole story. As an example, I used Ammo Lock in one tank, and my API test kept showing 2
PPM. I found that Seachem makes a
test kit that measure both free ammonia, and total ammonia. I couldn't find the Seachem test at Petsmart or Petco, so I had to order it online (Foster & Smith). Anyway, the Seachem test showed that I had 0 free (toxic) ammonia, and also confirmed the 2ppm total ammonia that I got with the API test. When I saw that I knew that my water was under control and the tank had cycled.
The Seachem test is a little more difficult to run - you have to use a tweezers (supplied) to pick up a tiny, flimsy, yellow (reusable) disk, place it in a water sample, and then wait 1/2 hour before you compare the color of the disk to a color chart. You have to use the tweezers to rinse the tiny disks in tap water before & after using, and hope that you don't lose one down the drain (they give you 6 though). After the test is done, and you've rinsed & returned the disk to the little plastic container they come in, they will recharge and turn yellow again. If you want to measure total ammonia you have to add a drop of a supplied solution to a second water sample. I usually just run the free ammonia test, since that's what really important.
But, aside from the test being a bit more difficult to run, it's nice to know how much of the toxic free ammonia you really have in a tank. I think Seachem also sells these little ammonia monitors that you keep in a tank - I have a feeling that those also measure only free ammonia. These I did see at Petsmart, and I'll pick one up on the next trip to see if it agrees with the Seachem test kit.
http://www.seachem.com/products/prod...MTAmmonia.html
There's the link to the Seachem test.