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Water change twice a week, do you still need a day off of EI fertz?

ForestDave

Member
Joined
12 Nov 2020
Messages
279
Location
Forest of Dean
Hi.
I use EI fertz on alternate days but do a water change twice a week not once. Does it still make sense to have a day off the fertz once a week or does the extra water change do the equivalent?
George Farmer recommends water changes twice a week to cut down on algae, this seems a good alternative to using glute which my creatures definitely didn't seem happy with.
 

MichaelJ

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9 Feb 2021
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Location
Minnesota, USA
@ForestDave I am only vaguely familiar with the EI regime, so I don't know, but a lot of experts here will however. I suppose it depends on the dosing, percentage of water you are changing each time and if your running CO2 etc.

I am running two densely planted low-energy tanks and do around 40% WC each week with dosing at the same time and then again mid week - I run my tanks at high NPK levels and low light intensity. I have good plant health and no algae to speak of.

Cheers,
Michael
 
Last edited:

Andy Pierce

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Joined
27 Nov 2020
Messages
156
Location
Cambridge, UK
I do EI dosing and it does make sense to me to skip the day off if you are doing water changes twice a week instead of once. That being said, I don't think it will make a big difference one way or the other (EI by design doesn't really get too hung up on exact calculations) and if it's easier to remember to dose on MWF I would just keep on with that. For what it's worth I think George has missed the mark on this one. If you've have algae problems with EI dosing (are you also using injected CO2 gas?), those problems likely relate to too much light rather than not enough water changes.
 

Zeus.

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1 Oct 2016
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Yorkshire,UK
I dose straight after a WC every time. The reason being is EI dosing as all about ferts in abundance, once you have done a WC the ferts and toxins/DOCs (Dissolved Organic Compounds) will both be at their lowest potential concentrations. Yes you tap water may or may not have NO3, K, PO4 etc however it may not have much or any if using RO water. So dosing straight after a WC makes sure the ferts are in abundance.
 

ceg4048

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UKAPS Team
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11 Jul 2007
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Chicago, USA
Hi.
I use EI fertz on alternate days but do a water change twice a week not once. Does it still make sense to have a day off the fertz once a week or does the extra water change do the equivalent?
George Farmer recommends water changes twice a week to cut down on algae, this seems a good alternative to using glute which my creatures definitely didn't seem happy with.
Hello,
You can do whichever suits you. You can have a rest day or not. That is the beauty of EI. You are not compelled to be manic about the details or schedules because EI provides plenty of reserve nutrients in the water, in the sediment and in the plants tissues themselves.

Regarding the water change schedule, multiple changes per week is good to do for the first month to six weeks of initiating the tank. As zeus mentions, the plants produce a lot of organic waste - more waste even than fish, and they can be stifled by their own waste.
Once established however, the two changes per week will not really be necessary unless you have overcrowding or overfeeding etc. You can then revert to a single change per week of the suggested 50% tank volume or more. George knows that keeping the water (and filter) clean is among the most important factors in success, but it is very easy to burn out on water changes, especially as tank size increases.

Cheers,
 

ForestDave

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Thread starter
Joined
12 Nov 2020
Messages
279
Location
Forest of Dean
Hello,
You can do whichever suits you. You can have a rest day or not. That is the beauty of EI. You are not compelled to be manic about the details or schedules because EI provides plenty of reserve nutrients in the water, in the sediment and in the plants tissues themselves.

Regarding the water change schedule, multiple changes per week is good to do for the first month to six weeks of initiating the tank. As zeus mentions, the plants produce a lot of organic waste - more waste even than fish, and they can be stifled by their own waste.
Once established however, the two changes per week will not really be necessary unless you have overcrowding or overfeeding etc. You can then revert to a single change per week of the suggested 50% tank volume or more. George knows that keeping the water (and filter) clean is among the most important factors in success, but it is very easy to burn out on water changes, especially as tank size increases.

Cheers,
Thanks. I totally agree. Having read the other responses and yours I'll definitely move to a water change once a week, I probably spent far too long changing the water every other day so even twice a week seems a lot at the moment and I was starting to question why I signed myself up to all this work when I've got a ton of other things which need doing around the house. I was just massively paranoid about getting a tank full of algae.
All seems reasonably good in my tank apart from a tiny bit of BBA on a few crypt leaves and some green thread spirogyra algae here and there. That's my fault for increasing the light too much as an experiment. I'm just going to leave it as 2x39w T5s on my Roma 200 litre tank for the time being. It looks nicer with x4 tubes but I always seem to upset the balance when I try for that.
Thanks Ceg and other posters!
 

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