EI method for daily water change??

ScottM

New Member
Sep 18, 2021
4
2
3
SoCal
okay so I have 2 tanks that both have breeding colonies of shrimp and some plants in them. after lots of research on shrimp it is recommended to do several small water changes per week that are slow drip back into the tank and I would like to try the EI fertilizer method non c02.
My question is that I'm thinking of doing a daily 7% water change that will equate to a total of 50% water change per week. the other thing I was thing to save some time was a little weekly per prep all the water that will go into to the tanks each day with all the nutrients.
so if I want to maintain say 10 ppm's of N03 would I prepared the water with 5 ppm's N03 or 10 ppm's?
I hope this isn't to confusing and Im have troubles wrapping my brain around it.
 

Allwissend

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i think i understand what you want to do. First thing first, Seven 7% waterchanges are not the same as one 49% waterchange. Say you start with water with a NO3 of 10 mg/L and your replacement water has 0 NO3.

A) one 49% water change
before (mg/L NO3)after (mg/L NO3)
105.1

B) seven 7% water changes

water change #before (mg/L NO3) after (mg/L NO3)
1109.3
29.38.65
38.658
487.5
57.57
676.5
76.56

It will actually take about ten 7% water changes to reduce the nitrate(as an example) concentration to the same value as a 50% water change. It will take seven 10% water changes to get to about the same target. And that does not consider any nitrates produced by the shrimp in that time or added with fertilization. Nothing wrong with it but just be careful of this aspect.

Second, if your water has 10 mg/L NO3 and you want to keep it exactly there you would add water that also has 10mg/L NO3. This will not dilute or increase the concentration... theoretically.

In practice, things as evaporation and shrimp /bacteria metabolism will increase your nitrate concentration. Plant uptake will deplete the nitrate concentration. So there will always be 2 moving factors affecting that target of 10. The great news is that most plants can adapt over a wide range of nutrients. So try and see how it is for your shrimp with the 10 mg/L in the replacement water and if needed increase or decrease it.
 

ScottM

New Member
Sep 18, 2021
4
2
3
SoCal
i think i understand what you want to do. First thing first, Seven 7% waterchanges are not the same as one 49% waterchange. Say you start with water with a NO3 of 10 mg/L and your replacement water has 0 NO3.

A) one 49% water change
before (mg/L NO3)after (mg/L NO3)
105.1

B) seven 7% water changes

water change #before (mg/L NO3)after (mg/L NO3)
1109.3
29.38.65
38.658
487.5
57.57
676.5
76.56

It will actually take about ten 7% water changes to reduce the nitrate(as an example) concentration to the same value as a 50% water change. It will take seven 10% water changes to get to about the same target. And that does not consider any nitrates produced by the shrimp in that time or added with fertilization. Nothing wrong with it but just be careful of this aspect.

Second, if your water has 10 mg/L NO3 and you want to keep it exactly there you would add water that also has 10mg/L NO3. This will not dilute or increase the concentration... theoretically.

In practice, things as evaporation and shrimp /bacteria metabolism will increase your nitrate concentration. Plant uptake will deplete the nitrate concentration. So there will always be 2 moving factors affecting that target of 10. The great news is that most plants can adapt over a wide range of nutrients. So try and see how it is for your shrimp with the 10 mg/L in the replacement water and if needed increase or decrease it.
Allwissend thank you for breaking it down for me and i figure I'd test the water peramitors in a few weeks to see how it's going. I have been doing the daily changes now for just a few days and im seeing a good response already in the plants but i think it also has to do to the fact that the nutrients are balanced that im using now