High and Low range Nitrate test kits

[Freddy Twotimes]

I have been discovering a huge difference between the accuracy between test kits. I have found the the AP brand is good for ammonia and nitrite, I am going to buy a refractometer for SG tests and I just got a probe for PH.

A LFS told me that the AP Nitrate test kit is best for fish tanks because it is a good test kit when trying to test higher levels and that I should try a Salafert for a low range Nitrate. Can anyone tell me what a good test kit is for measuring Nitrate below 20ppm? I am looking for more opinions regarding test kits for Nitrate at low levels.

PS

Is anyone maintaining a tank with Nitrate levels between 10-20ppm in a reef tank without a overgrowth of algae? My tank just cycled and I am ready for the cleanup crew and was just curious about this before I start running the light 8 hours a day...

[Ninong]

LaMotte makes an excellent low-range nitrate test kit but if you want to spend less money, Salifert's nitrate test kit is a good value. Kits that are much cheaper than that are probably a waste of money.

David Saxby's reef aquarium in his London flat has been running sucessfully for many years with nitrate levels between 10-20 ppm. He used to say it was 20 ppm in earlier publications but lately he's been claiming 10 ppm. Total water volume in the L-shaped tank itself is approximately 1,200 gallons but he has a lot of sump capacity that greatly increases the total water volume in the system.

[Freddy Twotimes]

Thank you for the reply, I had another question...

In laymons terms 'is it necessary to have low levels of Nitrate in an aquarium for the heatlh of the corals?'

A LFS told me that some levels of Nitrate was needed for overgrowth of cells or something? Do you know what that means or does that make any sense to you at all?

[Ninong]

In laymons terms 'is it necessary to have low levels of Nitrate in an aquarium for the heatlh of the corals?'

The goal should be to replicate natural conditions as much as possible. The waters over typical tropical coral reefs are oligotrophic. That means that they are extremely low in nutrients. How low? Well, typical nitrate (NO3) levels are 0.003-0.03 ppm with a reported range of 0.003-0.6 ppm. In other words, nitrate in the waters over coral reefs is much less than 1 ppm.

It is considered desirable to maintain nitrate levels below 10 ppm for an SPS-dominated reef aquarium and below 20 ppm for a mixed reef aquarium. That's not the goal, just the levels that most people would not want to exceed. The goal for a typical SPS-dominated reef aquarium should be nitrate levels below 5 ppm. Most hobbyists in the U.S. shoot for nitrate levels below 3 ppm.

If your aquarium measures 1 ppm nitrate, that's more than enough nitrate to meet all the demands of anything in your tank, including clams. I know of one well known hobbyist whose 718-gal reef aquarium contains more than two dozen large clams and his nitrate levels are consistently less than 1 ppm. Actually the clams help to maintain the low levels of nitrate in his system. His SPS-dominated tank is very, very heavily stocked with corals, clams and fish.

A LFS told me that some levels of Nitrate was needed for overgrowth of cells or something? Do you know what that means or does that make any sense to you at all?

Ask the LFS person what level of nitrate he recommends to meet these demands? I'm just curious what his response will be. Whatever he tells you, your response should be, "Well, I wonder how the poor corals on the reefs manage to get by with less than 1 ppm nitrate?"