Nitrate cumulative

[kurt]

Assume that the tank inhabitants do not produce any nitrates.

When I test my tap water it registers 20ppm. Test jug I used held one gallon of water. If I add 3 gallons to my tank, will I have a reading of 60 (argument sake) or should it stay at 20.

What can I use to get rid of the nitrate from my tap water? Will a RO system work or how about if I let the water sit for 24 hours.

Kurt

 

[stotty]

Yes it should it stay at 20.
nitrate and nitrite
Nitrite is the result of the metabolism of ammonia by Nitrosomonas bacteria.This oxidize ammonia (NH3) and convert it into nitrite (NO2). one step further and further oxidize the nitrites into Nitrates (NO3).
It is unavoidable to have nitrite in a tank that is new. The nitrogen cycle is not complete because there are not yet enough bacteria to treat ammonia and nitrite. If its below 20 normaly ok.In your tank if you have this problem there are too many fish or not enough filtration.Nitrate removal filter media will work to some extent, but larger water changes will be the most effective solution But if its from the tap, RO units have several advantages over tap water . The water comes from the tap, which is usually safe and is filtered by a fine sediment filter and carbon block before it enters the RO chamber. Once it passes through the membrane, many units also pass the water through one or more deionizing units. This results in very pure water that is low in organics, dissolved minerals and nutrient compounds. One side effect from using a RO Unit is that they will remove some of the "good stuff" along with the "bad stuff". Because of this you will need to add the "good stuff" (minerals and other essential elements) back into the water before using it in your aquarium.Many tropical fish hobbyists have been keeping fish successfully for years without using a Reverse Osmosis Unit. RO units I have one and use 50/50 rain water and RO but this opens another can of worms .

 

[Jesse]

Think of it this way, your nitrate concentration is in parts per million. Thus, you have 20 parts of nitrate for each million parts of water. For every gallon you add from the same source, you will also have 20 parts of nitrate for each million parts of water. Assume for illustrative purposes that you have 20 nitrate ions in a million molecules of water in each gallon. Based on this assumption, you would have 60 nitrate ions and three million molecules of water in 3 gallons or a ratio of 20 parts nitrate per million parts water. In other words, the total nitrate concentration doesn't go up because each gallon you add has the same amount of water to dilute the nitrate.

 

[kurt]

Thanks for the info.

Kurt

 

[HarleyK]

Howdy Kurt, and welcome to MFK!

Your reading of 20 ppm is a concentration, and, thus, independent of volume.

The nitrate level in your tap water is high, but still managable depending on your bioload. You could introduce some plants, e.g. fast-growing floating plants do a great job reducing nitrates.

HarleyK

 

[kurt]

I have introduced plants and it did not reduce my Nitrate level but it did get rid of most of the algae. I did notice when I do a couple of water changes in a week it will lower my Nitrates about 20 to 40 ppm. The fish do not seem to mind the high Nitrate levels. There are only two goldfish in a 30gal with a 300-gph power filter. They are growing out of the tank. Will need to upgrade. Thinking about a 120gal.

Since I do not have a RO unit, will letting the water sit for a day or two reduce the nitrate levels.

Thanks,

Kurt

 

[HarleyK]

I have introduced plants and it did not reduce my Nitrate level but it did get rid of most of the algae.

The regular water changes your mentioned are a great solution to your problem!

Since I do not have a RO unit, will letting the water sit for a day or two reduce the nitrate levels.

Letting water sit does not reduce nitrate levels. Hobbyists did it in the old days to get rid of chlorine. Nowadays, a good dose of water conditioner saves you from having buckets stand around in your living room

HarleyK

 

[Jesse]

Reducing nitrate concentrations by doing water changes is a simple linear calculation. For example, if your tank has a nitrate concentration of 60 ppm and you do a 50 percent water change replacing it w/ your 20 ppm tap water, your resultant nitrate concentration immediately after the water change will be 40 ppm, calculated as follows:

(nitrate concentration of water that stays in the tank x percentage of whole) + (nitrate concentration of new water added x percentage of whole) = resultant nitrate concentration after the water change

(60 ppm x 0.50) + (20 ppm x 0.50) = 40 ppm.

You can up your nitrate reduction by doing 75% water changes as follows:

(60 ppm x 0.25) + (20 ppm x 0.75) = 30 ppm.

 

[ewurm]

Nice math! Doesn't 20ppm nitrate in tap water sound high?

 

[Jesse]

Doesn't 20ppm nitrate in tap water sound high?

I based my example on Kurt's tap water. Fortunately, my tap water is 0 ppm or close to it.