# EI ratio question



## swackett (6 Jun 2017)

I've read that I should be aiming for 10:1 ratio of NO3 : PO4, however is this really NO3 : PO4 or a ratio of N : P and is this old advice?

Also if PO4 is higher than that does that cause an imbalance and thus can cause algae issue? Then again I've read that you can add more PO4 without issues and so this brings into question the 10:1 ratio.

Rotala Butterfly suggest 30ppm of NO3 to 5.2ppm of PO4, so clearly not 10:1.


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## dw1305 (6 Jun 2017)

Hi all,





swackett said:


> I've read that I should be aiming for 10:1 ratio of NO3 : PO4, however is this really NO3 : PO4 or a ratio of N : P and is this old advice?


Plants need more nitrogen than phosphorus, but I think the actual numbers are derived from the <"Redfield Ratio">.

cheers Darrel


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## swackett (6 Jun 2017)

dw1305 said:


> Hi all,Plants need more nitrogen than phosphorus, but I think the actual numbers are derived from the <"Redfield Ratio">.
> 
> cheers Darrel



Thanks Darrell,  should I follow the article by Clive as that seems to have 10:1 ratio seems more in line with what I have read?
https://www.ukaps.org/index.php?page=dosing-with-dry-salts


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## AverageWhiteBloke (6 Jun 2017)

Confusing eh? I've had this discussion before as some calculators seem to contradict each other. The E.I is a range and most seem to be the same just aiming for different targets. The range taken from UKAPS and most places to be fair are as follows.

Nitrate (NO3) 20ppm per week
Potassium (K) 30ppm per week
Phosphate (PO4) 3ppm per week
Magnesium (Mg) 10ppm per week
Iron (Fe) 0.5ppm per week

Now other calculators will aim for 30 ppm no3 to 20ppm and 1ppm to 3ppm po4 weekly. Checking James planted tank that would suggest 0.186 grams in 100ltr tank for 1.3ppm dosed 3 times per week. As would Rotala Butterfly same again 0.186=1.3ppm but says dose 2 or 4 times a week. So again they are aiming for a range of between 1/3ppm weekly. The only anomaly is The Nutrient Company which for some reason seems to be trying to aim for 9ppm weekly! That's what blew my mind and I couldn't figure whether we were dealing with n or no3 or p or po4. 

It's not exact science BTW, as Darrel mentioned plants consume mostly nitrate and potassium and the rest for a balanced diet. I assume 30ppm no3 and 3ppm po4 to be top of the shop unlimited with good flow. I then work my way down from there but at the same ratio. In my tank though I bear in mind that my tank creates it's own nitrogen from fish waste but not much po4 other than from fish food so I reckon the no3 will fall slower than the po4 in a well lit tank. Once you start rolling back if that's what you want to do at the top numbers there is enough potassium in both the kno3 and po4 but as these levels get lower you may need to add extra potassium in the form of potassium sulphate. Cross that bridge if you get to that.

I have a 500ml bottle mixed at the Nutrient company's recommendation of very high po4 which I gave up on, I may try and get my head around it later as it happens and see if I can mix a bottle which just kno3 in and combine the two.


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## swackett (6 Jun 2017)

AverageWhiteBloke said:


> Confusing eh? I've had this discussion before as some calculators seem to contradict each other. The E.I is a range and most seem to be the same just aiming for different targets. The range taken from UKAPS and most places to be fair are as follows.
> 
> Nitrate (NO3) 20ppm per week
> Potassium (K) 30ppm per week
> ...



So the 10:1 ratio for no3 and po4 is what to aim for?


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## swackett (6 Jun 2017)

Adding up the Mg, it looks like i need to add 27 tsp to 500ml of water to get total 10ppm a week dosing 10ml 3 times a week.  Is this right as it seems a lot of tsp's to me.

Also how do you get the 10:1 balance using KN03 and KH2PO4 ? Do I need to use K2SO4?


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## AverageWhiteBloke (6 Jun 2017)

swackett said:


> So the 10:1 ratio for no3 and po4 is what to aim for?



I would, keep it simple. You can adjust later if needs be. The point of EI is to have nothing limiting and those figures are deemed as theoretically nothing limiting. As you reduce your dosing, if that's what you are aiming for you can keep an eye out deficiency, soon as that happens you have hit the critical point where your nutrients are running out before WC day then you roll the dosing up a little as you've found your point. Problem is this is a moving target as plants increase and why many people will just dose EI all the time regardless. That's where the TDS pen comes in handy. If your TDS is steadily rising over the months you can assume you’re putting too much ferts in and can either reduce the dosing or increase the wc's. Increasing wc's is probably the more fail safe option but that depends on how much time you have on your hands. I personally like to keep my tds a bit lower because I have soft water fish stocked.



swackett said:


> Adding up the Mg, it looks like i need to add 27 tsp to 500ml of water to get total 10ppm a week dosing 10ml 3 times a week. Is this right as it seems a lot of tsp's to me.



No that's about right. I think Mag is what you do add most of dry. Maybe there's not a great deal of actual magnesium in there relative to the other elements in epsom salts. Either way, mag is not as critical as other in the same way as trace elements. My tank is the same size as yours, supposedly 125ltr but more realistically about 100. That happens to be an easy to remember figure as 5gram of epsom salts adds 5ppm magnesium to a 100 ltr tank. The range for EI is 5 to 10ppm weekly. I've tried with various teaspoons and pretty much if you level one it will be approx 5 grams so I just dump one in on wc day. My tap water has no magnesium at all and I get by on that so you should be ok with harder water.




swackett said:


> Also how do you get the 10:1 balance using KN03 and KH2PO4 ? Do I need to use K2SO4?



You shouldn't have to add any potassium sulphate when dosing ei, there is enough in the kno3 and po4. You only maybe need to add some if you start dosing the kno3 and po4 leaner as that's where most of your K comes from.


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## AverageWhiteBloke (6 Jun 2017)

I knocked this up a while back based on dosing 30ppm no3 and 3ppm po4 weekly. You can see from that you could down a bit with your dosing before you need to start worrying about potassium. Obviously that's a straight forward EI 500ml bottle but as you are using Tropica products in parallel you will have to juggle the numbers a bit to factor that in.


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## swackett (6 Jun 2017)

AverageWhiteBloke said:


> I knocked this up a while back based on dosing 30ppm no3 and 3ppm po4 weekly. You can see from that you could down a bit with your dosing before you need to start worrying about potassium. Obviously that's a straight forward EI 500ml bottle but as you are using Tropica products in parallel you will have to juggle the numbers a bit to factor that in.
> 
> View attachment 105784



Is the 10:1 ratio the ratio of NO3 compared to PO4 in terms of PPM, rather than the quantity of the salt you add to your solution bottle as the percentage of NO3 in KNO3 is not the same as the percentage of PO4 in KH2PO4 ?   So my question regarding K2S04 is because I think using just KNO3 and KH2PO4 means you can never get a 10:1 ratio of NO3 : PO4.


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## AverageWhiteBloke (6 Jun 2017)

Good question, something I never got to the bottom of if I can find that post again, wasn't exactly sure whether at times we were dealing with nitrogen or nitrate values or phosphorous and phosphate values. However, I have correlated virtually every recipe I've came across in various places and they all seem to have give or take the same recipes. The main thing to remember is the plants only want some of each and to make sure none runs out. It's not like the plants are saying right I want 10ppm no3 then 1ppm po4 then with light and carbon I'll start building. If the ferts are there in any quantities they will just use it. Basically EI worked out that with something like from memory 4 watts per gallon lighting plants didn't consume any more of any so it was decided adding any more is just a waste. In fact could cause problems as having too much of one could cancel out another making it inaccessible to plants. But let's no go there right now unless you're looking for a bad head. 

I wouldn’t get too bogged down in the numbers or the 10.1 ratio. As I said earlier nitrogen is added to the system as you go along so if you did get the exact to the decimal point ratio of 10.1 within a day of it going in it would already be down the pan. Based on your tank, which if I'm honest is actually doing great. other than a couple of issues you've came across with a couple of species I would say what you are doing already isn't far for the sweet spot. I would just mix up a bottle based on those standard set of figures and using a syringe dose some at whatever you think until you stop having issues.


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## AverageWhiteBloke (6 Jun 2017)

Thought I'd throw this in as well which is handy. I always use it for a quick reference when I'm gaping into my tank. It's not a definitive guide and as I mentioned people who dose real heavy can come across issues where for instance too much of one can cancel out the other like too much po4 reacting with iron then you get the situation where they say can't be iron because I'm dosing loads of it. Now in your case you had a few new leaves that didn't look right which suggested iron but you also had old leaves and dissolving plants which would in my eyes anyway suggest more like nitrogen especially when we have established that dosing just Tropica doesn't give you a lot of nitrogen. If you made up a bottle and dosed low end of EI for a while alongside your Tropica and see if there's an improvement in the situation. If so you've cracked it. I feel though after a while you'll probably just end up dosing dry salts.


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## swackett (6 Jun 2017)

Yes thanks, the 10:1 ratio works with PPM as far as I can tell.  By looking at the EI guide that Clive wrote, 30ppm of NO3 and 3ppm of PO4, so 10 : 1.

Yes I understand its not an exact science, but just curious


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## AverageWhiteBloke (6 Jun 2017)

I'm like that myself, even if it doesn't matter. Somebody asks me what time is I start taking a watch to bits


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## ceg4048 (16 Aug 2017)

swackett said:


> Yes thanks, the 10:1 ratio works with PPM as far as I can tell. By looking at the EI guide that Clive wrote, 30ppm of NO3 and 3ppm of PO4, so 10 : 1.
> 
> Yes I understand its not an exact science, but just curious


Your life will be much simpler if you forget about ratios.
EI does not care about ratios and really, as far as we are concerned, our plants do not care about ratios either.
Nitrate is consumed at a very high rate as it is used in almost every function that a plant has. The Nitrogen is used in building proteins and enzymes.
Phosphate on the other hand, is a recyclable component and so is re-used constantly as it is used in energy production and consumption. So the plant does not need to scrounge around for lots of phosphate, which is a good thing because phosphate is in extremely limited quantities in nature. So it's easy for someone to cut a plant open and count molecules and then do some math to get a ratio, but that does not automatically mean that you need to dose in that ratio. Just follow the guide and the plant will take what it needs.

EI numbers were not derived from silly ratios. The plants were simply fed as much as they could consume. When no further improvement was seen the numbers that were used in the exercise were revealed. So just use those numbers without fear. If you want to use less or more then again, do so without fear and never worry about ratio. 

In dosing any fertilizer method you only ever need to worry about whether the plants are getting healthier. Whatever numbers or ratios result in healthy plants is considered goodness.

Cheers,


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## rusticdr (16 Aug 2017)

ceg4048 said:


> Your life will be much simpler if you forget about ratios.
> EI does not care about ratios and really, as far as we are concerned, our plants do not care about ratios either.
> Nitrate is consumed at a very high rate as it is used in almost every function that a plant has. The Nitrogen is used in building proteins and enzymes.
> Phosphate on the other hand, is a recyclable component and so is re-used constantly as it is used in energy production and consumption. So the plant does not need to scrounge around for lots of phosphate, which is a good thing because phosphate is in extremely limited quantities in nature. So it's easy for someone to cut a plant open and count molecules and then do some math to get a ratio, but that does not automatically mean that you need to dose in that ratio. Just follow the guide and the plant will take what it needs.
> ...


Well said. I have been following ukaps for a over a year now and I should say that I am a big fan of ur posts. Have learnt a lot and I think it's the way u explain things. It's very simple but scientific too. I hope u keep finding the time to enlighten more souls like mine in this awesome hobby. Tc. 

Sent from my SM-G920I using Tapatalk


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## swackett (16 Aug 2017)

ceg4048 said:


> Your life will be much simpler if you forget about ratios.
> EI does not care about ratios and really, as far as we are concerned, our plants do not care about ratios either.
> Nitrate is consumed at a very high rate as it is used in almost every function that a plant has. The Nitrogen is used in building proteins and enzymes.
> Phosphate on the other hand, is a recyclable component and so is re-used constantly as it is used in energy production and consumption. So the plant does not need to scrounge around for lots of phosphate, which is a good thing because phosphate is in extremely limited quantities in nature. So it's easy for someone to cut a plant open and count molecules and then do some math to get a ratio, but that does not automatically mean that you need to dose in that ratio. Just follow the guide and the plant will take what it needs.
> ...


Yes agree, well that's what I later found out.  However a lot of articles I was reading mentioned rations of 10:1 which is why I posted the questions.

I still not having great success with some plants in the tank which just melted away over a few weeks so I guess something is still not quite right somewhere.


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## ceg4048 (18 Aug 2017)

swackett said:


> I still not having great success with some plants in the tank which just melted away over a few weeks so I guess something is still not quite right somewhere.



Hi,
    Melting plants is a result of poor CO2 or poor distribution of CO2 due to disrupted or incoherent flow. Since the topic of discussion EI I will assume we are talking about a CO2 enriched tank.

If this is the case then your energy would be better spent attacking the problem of CO2/flow/distribution and perhaps also casting a critical eye on light intensity reduction, as these parameters are directly related.



rusticdr said:


> Well said. I have been following ukaps for a over a year now and I should say that I am a big fan of ur posts. Have learnt a lot and I think it's the way u explain things. It's very simple but scientific too. I hope u keep finding the time to enlighten more souls like mine in this awesome hobby.


Thanks for the very kind words mate. Greatly appreciated.

Cheers,


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