PPM

PPM - Parts per million.
Paludarium - An aquarium that is set up with a dry land area as well as a water area.

CO2 (in PPM) = 3xKH x10(7-pH)
where KH is KH in degrees.
(Formula from Chuck Gadd)
If your test kit for KH is in ppm or mg/L, you can convert to dKH by dividing the test result by 17.9 (i.e. 1 dKH=17.9 ppm).

tank I have 143 PPM of calcium and the Pillow takes out 140 PPM in a 48 hour period...how many hours can I leave it in to get 100 PPM of hardness...hahahahahaha...

Saltwater is comprised of many elements at different concentrations or Parts Per Million (PPM).

Also, if the calcium levels are maintained above 350 PPM, the coralline algae will compete for attachment sites. In freshwater aquariums, some success has been reported using Glass (Ghost) Shrimp to control hair algae.

A new theory on swim bladder disease is that chronic exposure to nitrate levels of 30 PPM and higher causes a swim bladder problem. Increased nitrates have a sedative affect on the fish and cause a paralysis of the gastrointestinal system.

A water hardness of 20 to 110 PPM is recommended. A palate of beef heart, krill, and flake foods should be fed to the Discus. They should not be given any worms, because they contain parasites that will infect the Discus.

Figuring the change in aquarium concentration of Fe (or any element) after a single PMDD dose
Increase in Concentration in PPM = (PMDD concentration of element)*(Dose)/(water column) in mG/ltr or PPM in ltr in ltr ...

I don't think there is a solid-state sensor technology to give me nitrite and nitrate PPM or an ammonia alarm function, but that is what would seal the deal for me; the ability to detect a tank gone whack-o and beep at me.

Alkalinity - Sometimes referred to as Carbonate Hardness. The amount of your aquarium water's ability to resist changes in pH. The alkalinity can be raised by using a catalyst such as baking soda. Alkalinity is usually expressed in PPM (parts per ...

The amount of your aquarium water's
ability to resist changes in pH. The alkalinity can be raised by using a buffer such as
baking soda. Alkalinity is usually expressed in PPM (parts per million) or dKH (German
degrees of hardness).

See also: Water, Aquarium, Fish, Color, Algae