Advice On Ei Please

[julia298]

Have been dosing EI for 2 weeks now. For the past week I have been following the EI routine in the pinned article.

I am on day 7 and am wondering whether i really need to do a 50% water change or any water change.
There are no fish in the tank.

My plants are using up the ferts as fast as I am putting them in so I am still raising nitrate slowly (about 5.0 at mo). Not sure about K and Fe as I cant test those, but Phosphate and Nitrate still very low.

So is water change necessary?
Thanks

 

[craynerd]

~Its a very interesting question and one i have given some thought to since i read it earlier this morning. Then i began to understand the problem.

The primary purpose of the water change is to "reset" the water chemistry, remove excess nutrients and restart the system.

You have said that your nutrients are all being used up, therefore i understand the logic behind your though. However, i think there is a bigger question that raises debate; Why are the nutrients at zero ?

The whole purpose of the EI is to provide a constant supply of nutrients.
The EI has its definition in its name; "estimative" therefore, it is an estimate dose schedule to change according to your own needs. I think that your current schedule of dosing is not sufficient for your plants if they are using them up and so I would increase the dose! This would then get rid of your argument, since then there would be an excess of nutrients in need of removing.

Besides everything I have just said, I think another major purpose of the water change is to get rid of algae spores that may be in the water!

You also do not know your Fe or K water concentrations, so without knowing what these are, you should reset them with a water change to be sure.

Besides the science behind it, i have a healthy comforting feel that changing the water is re-energizing and a refreshing change for your plants. How would you like to be bathed in the same water for a month! lol

Hope that helps.

Chris

 

[julia298]

I'm all for getting rid of algae spores.

Not sure about creating an excess of nutirents to then remove them... (I am still working on getting my doses right -Nirates deplete quickly & my tap water has 2.5 phosphates in it, so not quite sorted there yet).
But I suppose better to be safe ... as I dont know K & FE levels. I will stop being lazy and do a WC.

Thanks for your thoughts Chris.

 

[Jen]

I had the same thought when I first started. So one time I decided to leave it for 2 weeks, since changing 45 galons seemed like a whole lot of water to change. As I was doing my level checks the second week, the nitrate lever kept going up and up. I keep it at 20ppm, but 4 days after my scheduled water change my nitrates were up to 40, so I quickly did a water change to get them back to normal.

 

[craynerd]

Not sure about creating an excess of nutirents to then remove them... (I am still working on getting my doses right -Nirates deplete quickly & my tap water has 2.5 phosphates in it, so not quite sorted there yet).

Julia,

Plants need a constant steady supply of nutrients to grow and be healthy.
It has been shown that "excess" nutrients do not necessarly cause algae however you do not want to have constantly increasing nutrient levels. So its important that you create a constant supply which is of course going to qualify as an excess. You then do a water change to reset the levels and then start supplying them again to give a steady supply. The water change just stops the levels ticking up and up.

You should therefore be aiming to reach a dose scheme which proves just a little more nutrients than needed, not like you (and others) seem to be aiming for, which is a zero level at the end of the week! In actual fact, like i have just said, your doseing scheme should top up the levels throughout the week.

People may certainly have different thoughts on the matter, but this is the method i adopt and many succesfull aquascapers use. --------------------

Just looking at your post regarding figures. If you have 2.5 phosphate reading in tap water, thats great, free
fert. If your nitrates deplete quickly, you need to add more!!! IMO, give in excess and then water change to reset rather than give too little.

All within reason of course!!!

Regards

Chris

 

[julia298]

Thanks Chris,

I wasn't aiming for zero, thats just what my readings were every time i tested even tho i did keep upping the doses (i hadnt thought about the fact that I had also added a lot more plants). But was unsure about the WC.
But thats great information, things are a lot clearer now. Thanks for all the advice.