Join Date: Mar 2011
Location: Oregon State Beavers!
Estimative Index is for tanks that have adequate levels of CO2, moderate lighting, and good circulation. EI dosing regiment may not be exactly what you want with a lot tech setup, but the principles remain the same. The basic principle is providing all your nutrients in quantities large enough so that your tank never runs out of any particular nutrient.
The problem of course is how to tell how much nutrients your tank needs. Well EI works by estimating a dosing amount (per size of tank) that would result in all nutrients maintaining adequate levels. So you dose this amount on a predetermined time period (usually one week, but you can go for more) and then you do a 50 percent water change.
The benefit of this system is that you never have to worry about providing enough nutrients. You know what your tank's recommended dosage is and then you carry that out. As you learn the system better, you can better zero in on your "estimative levels" and give an even more accurate dosage. It's all about keeping all nutrients available to your plants.
The 50 percent water change ensures that you never have certain nutrients taking off in crazy amounts. To better explain: if I dose 1ppm of Phosphates every week and my plants only needed .5 ppm each week, every week my phosphates levels would be raising since my plants are consuming the "estimative dosage." To prevent this potential rise in levels, you do a 50 percent water change on a set schedule so the levels can never reach a certain point. If I did a 50 percent change every two weeks, then there is no way my ppm could ever pass 4. Even if my plants consumed nothing, I would add 1ppm during week one, another during week 2 (leaving me with 2ppm) and then I would do a 50 percent water change (brings it back down to 1 ppm) and add that weeks 1ppm and add next weeks ppm (brings me to 3) then do a 50 percent change. That leaves me a 1.5 ppm and the system goes on. 1.5 could only reach 3.5 before a 50 percent change which takes it to 1.75, which can only go to 3.75 before the water change. You will get infinitely closer to 4ppm tops, but never reaching it. I realize this is kind of confusing and I'm sorry if this doesn't help, but that is the basic format. Add nutrients in non-limiting quantities and then "reset" the system with a 50 percent water change on a set schedule.
Additionally, no one uses wpg as a helpful guide with lighting. Given the large number of types, intensities, distance between light and substrate, wpg is pretty useless. More specific information should be provided about what kind of lighting you have and how high it is from your substrate.
Last edited by Darkblade48; 08-01-2013 at 11:46 PM.
Reason: Please use the edit function for back to back posts to keep threads cleaner