# question on increasing ferts



## James Flexton (17 Sep 2014)

Hi,

Basically I want to increase the nitrate in the tank and am dosing EI KNO3 and KH2PO4

can I simply increase the KNO3 or should I also increase the KH2PO4 to keep the ratio of ferts the same?

ive got plenty of co2 in the tank and distribution/flow is fine, good growth but dwarf hairgrass and HC looks a slight bit more yellow than id like. only a hint of yellow but id like to nip it in the bud.


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## Edvet (17 Sep 2014)

I'd keep the ratio the same, just add more.


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## dw1305 (17 Sep 2014)

Hi all,





James Flexton said:


> Basically I want to increase the nitrate in the tank and am dosing EI KNO3 and KH2PO4can I simply increase the KNO3 or should I also increase the KH2PO4 to keep the ratio of ferts the same?


 You can just increase the amount of KNO3, it contains more potassium than nitrogen (39% K, 14%N), and plants need them in about the same amounts. Even though phosphorus (P) is the other macro-nutrient plants require much less of it.

The problem with most compounds that are higher in nitrogen, like urea (CO(NH2)2) or ammonium nitrate (NH3NO3) is that they contain (or are broken down to) ammonia.

cheers Darrel


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## ceg4048 (17 Sep 2014)

Jim,
     Ratios are irrelevant, so if there is a shortfall then one only needs to add what is missing. 
Having said that however, it doesn't really matter if you add more of everything, especially when it is not clear exactly which of the nutrients is in low supply.
What's more disturbing however is that you really should not be suffering any nutrient shortfall if you are dosing at EI levels so that means there is some fundamental issue gone awry, probably flow/distribution or miscalculation.

Cheers,


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## tim (17 Sep 2014)

Are you dosing magnesium ?


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## Jaap (17 Sep 2014)

James Flexton said:


> Hi,
> 
> Basically I want to increase the nitrate in the tank and am dosing EI KNO3 and KH2PO4
> 
> ...


Can u provide pics?


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## James Flexton (17 Sep 2014)

ceg4048 said:


> Jim,
> Ratios are irrelevant, so if there is a shortfall then one only needs to add what is missing.
> Having said that however, it doesn't really matter if you add more of everything, especially when it is not clear exactly which of the nutrients is in low supply.
> What's more disturbing however is that you really should not be suffering any nutrient shortfall if you are dosing at EI levels so that means there is some fundamental issue gone awry, probably flow/distribution or miscalculation.
> ...


i think im dosing standard EI.
KNO3 just over 1/4 tsp 3x per week
KH2PO4 just under 1/4 tsp 3 x per week
trace on middle days
2 days rest
water change on day one and start again...

pics below.
growth seems good its just not as lush green as id like. we are only 2 weeks in so it might just be emmersed growth from retailer dying off to be replaced by immersed growth.



 

 

 

 




tim said:


> Are you dosing magnesium ?



no. I have very hard water KH 17 ish so understand I dont need to.



Jaap said:


> Can u provide pics?


above...

cheers for the input guys


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## dw1305 (17 Sep 2014)

Hi all, 





James Flexton said:


> I have very hard water KH 17 ish so understand I dont need to.


 You still need to add magnesium, most of the aquifers in the UK are fairly pure limestone (often chalk) so just CaCO3 with very little "dolomitization". 

If you have hard water with a lot Ca++ ions it will interfere with plant uptake of Mg++ ions,  as will very high levels of K+ ions, so it is quite possible that you are seeing Mg deficiency symptoms. 

Magnesium  is mobile within the plant, so if you add some "Epsom Salts", and it is magnesium deficiency, you should see rapid greening.

In the USA things are different and a lot of their limestones (and aquifers) have quite a high proportion of magnesium present. 

cheers Darrel


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## James Flexton (17 Sep 2014)

ok so just off the shelf epsom salts yes? and how much to put in?



dw1305 said:


> Hi all,  You still need to add magnesium, most of the aquifers in the UK are fairly pure limestone (often chalk) so just CaCO3 with very little "dolomitization".
> 
> If you have hard water with a lot Ca++ ions it will interfere with plant uptake of Mg++ ions,  as will very high levels of K+ ions, so it is quite possible that you are seeing Mg deficiency symptoms.
> 
> ...


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## James Flexton (17 Sep 2014)

ok just bought some and looking at EI calc i have added 3.7g. ill do this from now on when dosing other macros


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## Jaap (17 Sep 2014)

In my experience and in my opinion they look fine. When did you plant them?


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## ian_m (17 Sep 2014)

James Flexton said:


> think im dosing standard EI.
> KNO3 just over 1/4 tsp 3x per week
> KH2PO4 just under 1/4 tsp 3 x per week
> trace on middle days
> ...


Bingo, issue is where is your magnesium ?

http://www.theplantedtank.co.uk/deficiencies.htm

It amazes me that people decide to deviate from all the work that into studying EI, role their own dosing schedule, based in information they don't have, miss out one of the cheapest ingredients and wonder why they have issues. Sorry to be negative (or offensive ?), but this happens here again and again. You can get 25kg magnesium sulphate for £18 delivered from a well known auction site. Whop it in, job done.


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## James Flexton (17 Sep 2014)

My excuse is I went from memory from 10 years ago which is when I last did EI. And forgot the Mg ha ha.


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## ceg4048 (17 Sep 2014)

The Nitrate dosing does not look right Jim. Not sure what the tank size is but the PO4 and NO3 should not be the same number.

Cheers,


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## ian_m (17 Sep 2014)

James Flexton said:


> My excuse is I went from memory from 10 years ago which is when I last did EI. And forgot the Mg ha ha


So 25kg of magnesium sulphate it is then at penance for being silly...apparently good for skin if you bath in it as well.


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## James Flexton (17 Sep 2014)

And constipation. Lol
Ceg, I'll post Tomorrow with the Grams per dose (dry dosing) of each. It's a 120L tank I think I worked it out based on 100L of water after displacement (ish).




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## James Flexton (18 Sep 2014)

ceg4048 said:


> The Nitrate dosing does not look right Jim. Not sure what the tank size is but the PO4 and NO3 should not be the same number.
> 
> Cheers,



Morning Clive,

so according to the nutrient calc for 100L i should be dosing the following

1.5g KNO3 (1/4 tsp)
0.58g KH2PO4 (1/8 tsp) (or half of a 1/4 tsp as i dont have a 1/8 measuring spoon)
3.7g MgSO4 (3/4 tsp)

im going more on weight rather than tsp's. i have small scale digital scales so have weighed out the above tsp's and worked out how much i need to dose as im not weighing powder every day.

so after double checking it now the KNO3 looks correct but i may have been slightly overdosing the KH2PO4 which isnt the end of the world.

However does this look like enough volume of each fert for the tank.

120L (100L after displacement) about 10bps co2 at the moment, good flow, no obstructions in tank for flow to circulate well.

i added the Epsom Salts last night and this morning it does look a little greener. but that might just be my bleary morning eyes seeing things through rose tints!


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## ceg4048 (18 Sep 2014)

The dosing is per tank size, not water volume. In any case the numbers are OK and the differences should not matter. If the Mg addition solves the problem then perfect.

Cheers,


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## ian_m (18 Sep 2014)

James Flexton said:


> this morning it does look a little greener. but that might just be my bleary morning eyes seeing things through rose tints!


Its the Matrix at work. You do some change to your tank, whether it be relevant (as in your case) or completely "wife's tale" and irrelevant, and the Matrix convinces you to see the result you were expecting.


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## dw1305 (20 Sep 2014)

Hi all, 





James Flexton said:


> ....added the Epsom Salts last night and this morning it does look a little greener. but that might just be my bleary morning eyes seeing things through rose tints!


 If it was magnesium deficiency could really be greener, magnesium is the central atom of the chlorophyll molecule and mobile within the plant, so you get a fairly instant greening effect on the newer leaves.


 
cheers Darrel


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## James Flexton (20 Sep 2014)

Thanks for sharing that explanation Darren, that makes perfect sense now. I'm pretty sure it has made a difference, so Mg must have been the issue. 


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## Jaap (21 Sep 2014)

If the water hardeness is 9kh does that mean there is enough Mg in the water?


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## dw1305 (21 Sep 2014)

Hi all, 





Jaap said:


> If the water hardeness is 9kh does that mean there is enough Mg in the water?


 The dKH is a measure of carbonates (as HCO3-), these will have come from the dissolution of a salt, usually it will be CaCO3,  because CaCO3 is the least soluble carbonate and builds up into large geological deposits under suitable situations for deposition ("limestone"). *But* the source of the carbonates can be other compounds like NaHCO3 (sodium bicarbonate), and doesn't necessarily add any dGH at all. 

General hardness (dGH) is a measure of the divalent cations, Mg++ and Ca++, but it doesn't tell you whether it is Ca++ or Mg++. In the UK a lot of aquifers are pure CaCO3 (often chalk), and this doesn't contain any magnesium. Limestone make have undergone dolomitization after their deposition, where some of the calcium has been replaced by  magnesium. This is the situation in the magnesian limestones in the UK that run N. from Nottingham to Durham or the Italian Dolomite Alps. 

Magnesium containing rocks usually originate from either volcanic action (like in New Zealand or Lake Tanganyika) or from evaporite deposits (like "Epsom salts"). Unless you know that your water contains magnesium you need to add it.

cheers Darrel


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## Jaap (21 Sep 2014)

dw1305 said:


> Hi all,  The dKH is a measure of carbonates (as HCO3-), these will have come from the dissolution of a salt, usually it will be CaCO3,  because CaCO3 is the least soluble carbonate and builds up into large geological deposits under suitable situations for deposition ("limestone"). *But* the source of the carbonates can be other compounds like NaHCO3 (sodium bicarbonate), and doesn't necessarily add any dGH at all.
> 
> General hardness (dGH) is a measure of the divalent cations, Mg++ and Ca++, but it doesn't tell you whether it is Ca++ or Mg++. In the UK a lot of aquifers are pure CaCO3 (often chalk), and this doesn't contain any magnesium. Limestone make have undergone dolomitization after their deposition, where some of the calcium has been replaced by  magnesium. This is the situation in the magnesian limestones in the UK that run N. from Nottingham to Durham or the Italian Dolomite Alps.
> 
> ...


if i dose epsom salts and water already contains Mg will this cause any problems to fish or plants?


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## dw1305 (21 Sep 2014)

Hi all,





Jaap said:


> if i dose epsom salts and water already contains Mg will this cause any problems to fish or plants?


No.

Darrel


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