# Estimative Index Questions



## Kypros (Apr 16, 2008)

Does anybody who uses the EI method of fertilization worry that the 50% water changes potentially may harm the fish? I get mixed results from experts on water changes. Some think 50% is okay, some believe that one should only do up to 30% at once? The EI method appeals to me because of the complexities of dosing ferts, etc.
Advice would be greatly appreciated.


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## ngb2322 (Apr 9, 2008)

I just began using the Seachem dosing chart, that is similar to EI. It calls for a 50% water change weekly as well, to make sure that any particular component of the ferts you are using does not accumulate within the tank. This accumulation, if unmitigated, could cause an imbalance in your tank's nutrients, possibly causing an algae explosion. Personally, I would say that when using EI change at least 1/3 of your water every week and if you notice problems with algae or fish in the tank change more each week. In regards to the animal inhabitants of your tank, it depends on their personal preferences whether or not they are affected by the ferts. Be sure to monitor your water to make sure that nothing is accumulating or out of balance and modify your fertilization technique by reducing or increasing one of the ferts to your tank.


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## hoppycalif (Apr 7, 2005)

I often change as much as 75% of the water in my 45 gallon tank, with no observable problems for the fish. In fact water changes seem to invigorate the fish, and that has been my observation for several tanks for several years. Healthy fish are not nearly as sensitive as you might think.

People raising discus generally do big daily or every other day water changes, just to keep clean water in the tank.


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## Left C (Jun 14, 2005)

I'm like hoppycalif. I do around 50% to 75% weekly water changes on all my tanks. I drain the water so that there is about 4" of water left above the substrate. I then fill them back up. While I am filling them; I dose Equilibrium and macros.

As hoppycalif mentioned, I also see that water changes seem to invigorate the fish. Sometimes they breed shortly afterward.


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## BiscuitSlayer (Apr 19, 2008)

The one thing I have noticed is that I loose less fish (ocasional die offs) by doing 50% water changes. 

Prior to going EI and performing large weekly water changes, loosing the occasional fish here and there was par for the course for me.


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## Minsc (May 7, 2006)

Doing frequent large water changes should keep the water very consistent with the tap, and not stress the fish. In an old, dirty tank, a sudden large water change could very well do more harm than good.

It is, as always, situational


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## Left C (Jun 14, 2005)

Most of my fish (tetras, otos, corys, etc.) freak out when I do a water change, Afterwards, they are very happy.

My cichlids know what's going on and they don't freak out.


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## Bert H (Mar 2, 2004)

Kypros said:


> Does anybody who uses the EI method of fertilization worry that the 50% water changes potentially may harm the fish? I get mixed results from experts on water changes. Some think 50% is okay, some believe that one should only do up to 30% at once? The EI method appeals to me because of the complexities of dosing ferts, etc.
> Advice would be greatly appreciated.


There are tons of us who do this with no ill effects whatsoever. As has been mentioned, I would say my fish actually do better with the changes than without it.


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## MatPat (Mar 22, 2004)

The only time I would worry about doing a 50% water change is on a tank that hasn't had consistent water changes like Minsc stated. If you haven't been keeping up with water changes you could stress the fish from the change in water parameters. Other than that, a 50% water change is fine.


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## Kypros (Apr 16, 2008)

Thank you all for your encouraging responses. I will try it!


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## Diana K (Dec 20, 2007)

If your tap water changes after sitting out for a day or so then you will probably want to age the water before a water change. As long as the new water matches the old water pretty closely large water changes are not a problem.


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## Tex Gal (Nov 1, 2007)

This is an age old question. I have read about this debate for years. Some people even change up to 90% of their water. TFH magazine had an article last year addressing this question. They talked to all the exerts. They could only agree on one thing. You should do regular water changes. I came away with the decision that the majority of weight fell in the 40-50% range.


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## hoppycalif (Apr 7, 2005)

Worldwide there are a lot of people changing about 50% of the water once a week, because they use the EI fertilizing method. No one seems to have fish problems as a result.


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## TWood (Dec 9, 2004)

I got into plants in the aquarium because I didn't want to have to change water to control nitrates. It works. I don't change water very often, maybe two or three times a year. I enjoy a relatively carefree aquarium and the fish do fine.

Plants are the toilet bowl cleaners, not an end unto themselves.


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## Kypros (Apr 16, 2008)

thank you all for your input on this matter


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