Aquatic Plant Forum banner
1 - 1 of 1 Posts

· Registered
4,333 Posts

When I work up a method for an EI tank I first start with a couple of assumptions.

First, the watercolumn of the tank is probably about 80% of the total volume. 150g * 0.8 = 120g.

Second, assume that you want a concentration of around 20 ppm NO3. Personally, that's a bit high for my taste, but it's ok. You change 1/2 of the water each week. If you assume that the plants don't use any NO3, you'll need to add 10ppm NO3 per week to get a concentration of 20ppm. Of course the plants do use some. Let's assume you add 20ppm per week. As long as you're faithful with your waterchanges, you'll never get a concentration >40ppm and it likley won't ever get lower than 20ppm.

Now, if you want to use an autodoser to add daily ferts, you'll need to add 2.86 ppm per day (20/7 = 2.86 ppm).

Using the fertilator, you'll see that 2.65 grams of dry KNO3 will produce 2.86ppm in 120 gallons of water.

If you use 2.65 grams per day, you'll need 967 grams per year (2.65 * 365 = 967). That's about 2.1 lbs per year.

Add 24 lbs per year and you'll have an average NO3 concentration of around 300 - 400 ppm per year, high enough that you'll cause major issues with the plants and probably the fish.
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.