# Fertilizing after a major water change.



## mattinmd (Aug 16, 2014)

Personally, I do water changes in the evenings, but this has to do with my free-time schedule. 

I dose Prime (to treat the new water), Flourish Comprehensive, Flourish Phosphorus and Equilibrium (GH/K) with my water changes. 

There's not much point to dosing Excel when the lights are about to go out, unless you are going to spot-treat algae. So I do NOT dose excel with my water changes.

I dose Excel (ok, I use API CO2 booster, same idea) daily, in the mornings right after my lights come on. I do this regardless of water change the evening before.

I do a mid-week second dose of Flourish comprehensive, Flourish Phosphorus, and Leaf Zone (K+Fe), and dose this one with one of my morning Excel doses.


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## hartgirl (Apr 23, 2014)

Ok good to know! I am changing my schedule to accommodate my day off. I had always dosed excel, flourish, and leaf zone with the water change and then again in about 4 days (excel daily in between as well). Then I read that Prime can completely negate the fertilizers for up to 24 hours after use, and that it uses excess O2 in the process (and thus starving fish of O2) ...anyways it made me wonder. 

Also is the API CO2 booster the same as Excel? Seachem says that you can dose anytime day or night because it stays active for 24 hours.

So for today I have done nothing. Just Prime, and ill add ferts and excel tomorrow around noon....well see how that goes lol...


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## Hoppy (Dec 24, 2005)

You want the plants to grow starting the minute you finish the water change, but you have removed about half of the nutrients that were in the water. So, you should immediately add the normal fertilizer doses after the water change. Just don't add both the iron and the phosphates at the same time, and especially not mixed together in water if you dissolve your fertilizers in water before adding them.


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## PortalMasteryRy (Oct 16, 2012)

I usually add trace, GH booster and some baking soda for 1 KH after a 50% water change. They are all half of the amount that I would add to the water column to get my desired parameters. Ex. If I used 1 tsp GH booster for 5 gallon then I'll only ad 1/2 tsp after my water change.


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## hartgirl (Apr 23, 2014)

Hoppy said:


> You want the plants to grow starting the minute you finish the water change, but you have removed about half of the nutrients that were in the water. So, you should immediately add the normal fertilizer doses after the water change. Just don't add both the iron and the phosphates at the same time, and especially not mixed together in water if you dissolve your fertilizers in water before adding them.


I dose Leaf Zone and Flourish Comprehensive twice weekly only for ferts, and then Excel daily (except I skipped today because I read that prime basically counteracts the ferts/excel within 24 hours) Should I not be adding the two fertilizers on the same day?


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## FatherLandDescendant (Jul 24, 2014)

hartgirl said:


> I read that prime basically counteracts the ferts/excel within 24 hours


Do you have a link for that info. I'd be real interested in reading that.


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## Jalopy (Aug 11, 2013)

Some people dose iron and phosphate on the same day. The reason is because the iron stays chelated if your water is acidic. That's how the all in one ferts work. I dose at night (micros and macros on alternate days) because I usually forget in the morning. Seems to work OK so far.


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## roadmaster (Nov 5, 2009)

I agree with dosing after water change for macros but I dose micros the following day due in large part to the dechlorinator I use (Prime) which claims to detoxify or remove heavy metals like IRON ?
It is unclear to me whether the iron in the trace minerals I use CSM+B is affected by the dechlorinators claims, so I does the micros the next day.
Would be happy to hear that the Iron as it appears in the trace mix is not affected to any measureable degree.?
Also am under the impression that mixing both together (macros/micros) has negative effect on phosphates or is it potassium? 
I understand you should not mix the two in same dosing bottle ,but am unclear about what effect it has if both are dosed the same day in the aquarium, and have noted that some /most don't add the macros and micros to the tank on the same day when dosing EI.
Am I messed up with my reasoning?


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## BruceF (Aug 5, 2011)

The situation is a bit different regarding the removal of nitrites and nitrates. Rather than physically breaking bonds within these molecules, Prime binds to the molecules themselves, thus making them unavailable to cause harm in the system. This bond will hold for up to 48 hours, until the nitrites and nitrates are consumed by the bacteria in the biofilter. (Aerobic bacteria consume nitrites and anaerobic bacteria consume nitrates.) Therefore, it is important to have both types of bacteria and sufficient surface area on which they can colonize, as LabTest57 alluded to. Again, we did not intend to mislead anyone, and we hope that this may clear some confusion.
http://www.seachem.com/support/forums/archive/index.php/t-2679.html
Notice they add prime day 7 and nothing else.
http://www.seachem.com/support/PlantDoseChart.pdf


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## hartgirl (Apr 23, 2014)

FatherLandDescendant said:


> hartgirl said:
> 
> 
> > I read that prime basically counteracts the ferts/excel within 24 hours
> ...


Well that last post pretty much sums up where I saw not to add ferts after prime. That and several frequent forum members mentioned it in other topics. I am not dosing trace and think I will start (opinions if you use Seachem Trace would be great!) I dose Leaf Zone for iron and potassium mostly because I have a giant bottle of it, but I am thinking about dosing seperately with Seachems line....do they make a test for potassium to get the desired amount? I know they have one or iron, but some people find them unreliable from what ive read...


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## FatherLandDescendant (Jul 24, 2014)

Go with dry ferts, you'll save a ton of money...

Ei concept: http://www.plantedtank.net/forums/showthread.php?t=517945

Dry dosing recipes: http://www.plantedtank.net/forums/showthread.php?t=647697 & http://www.plantedtank.net/forums/showthread.php?t=21944

This member sells dry ferts: http://www.plantedtank.net/forums/showthread.php?t=690881

You can also buy them here: http://greenleafaquariums.com/


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## mattinmd (Aug 16, 2014)

roadmaster said:


> I agree with dosing after water change for macros but I dose micros the following day due in large part to the dechlorinator I use (Prime) which claims to detoxify or remove heavy metals like IRON ?


Prime detoxifies metals by reducing them (in the chemistry sense, not the "less quantity" sense), it does not remove them. Detoxifying is not the same as neutralizing, removing, destroying, etc.

Based on that, it should not be counterproductive to add Prime at the same time as micronutrient fertilizers, even those containing metals. If anything, the reducing action should do things like convert any ferric iron (Fe+3) to Ferrous (Fe+2), which is more readily used by plants.


See this Q&A with seachem support, suggesting prime can be used in the dilution water for macros & micros.

http://www.seachem.com/support/forums/showthread.php?t=1041


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## mattcham (Mar 7, 2014)

BruceF said:


> http://www.seachem.com/support/PlantDoseChart.pdf


In that chart, the iron and phosphate are dosed at the same time. Is this an error? Or does seachem have a special formulation that allows macros and micros to be dosed simultaneously?


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## mattinmd (Aug 16, 2014)

As a follow-up, I contacted Seachem. They confirmed that Prime does not precipitate metals, and does interfere with Flourish Comprehensive, or any other Flourish fertilizer.




> Hello Matt,
> 
> Thank you for your email. Prime should not precipitate metals and will not interfere with Flourish Comprehensive or other products from our flourish line. It is safe to dose these products together.
> 
> ...


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## mattcham (Mar 7, 2014)

Hoppy said:


> Just don't add both the iron and the phosphates at the same time, and especially not mixed together in water if you dissolve your fertilizers in water before adding them.


I have seen this posted so many times and it seems to be an undisputed fact. For some reason the Seachem website, in their EI dosing instructions, mixes iron and phosphate together every other day. Anybody else notice this? That Seachem info has been online for more than a year.

http://www.seachem.com/support/PlantDoseChart.pdf


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## plantbrain (Dec 15, 2003)

I think under normal diluted concentrations in your tank, little of PO4 and iron are going to react. Even if they do, it's going somewhere, and the amount is small. 

So it's like dosing say 3 ppm instead of 2 ppm. Does not matter near as I can tell. I suppose you could argue if you wante dot squeeze every little bit of ppm efficacy out of the routine, but for 99.9% folks, this really does not matter.

Ferts are very cheap. 

I dose right after, I might dose initially the Traces right as I start to refill. Then after the water change and a few hours, I add the macros. I do the water change sin the morning right around the light cycle start. 

Never seen an issue.

Dechlorinators will reduce the Fe from Fe3+ to Fe2+, but...then O2 in your tank will oxidize back again. I believe chelators have little impact on reactions with dechlorinators(wastewater treatment folks are aware of this). At least something like ETDA, but not so sure about DTPA. 

I tend to dose 2x a week for macros, then daily if I remember, for the traces. 
Seems to work best after a long time of using various routines.


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## mattcham (Mar 7, 2014)

plantbrain said:


> I tend to dose 2x a week for macros, then daily if I remember, for the traces.
> Seems to work best after a long time of using various routines.


Interesting. Why 2x a week macros and ~7x a week traces? Is it because traces have a very short half life in the tank? I recognize that the macros and traces "traditionally" alternate every other day, but why not just 1 large dose 1x a week for macros and traces too?


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