All In One Solution

What is it?

After Tropica released their Plant Nutrition Plus, which is an 'All In One' dosing solution, I became interested in doing the same to make life easier for myself. Normally it is advised to keep potassium phosphate and iron traces in separate solutions to prevent any reaction occurring that results in an insoluble precipitate of iron (III) phosphate. The chelated traces that are used contain iron that is complexed and as long as the iron remains complexed it should be safe from any reaction with the phosphate. The problem is that once the traces are in solution the chelator tends to deteriorate and so releasing the the iron. I discovered that the chelators used are a lot more stable in a solution with a pH of 6 or less. After a bit of experimenting I ended up using E300 Ascorbic Acid (Vitamin C) which not only keeps the solution acidic but is also an anti-oxidant. Enough is used so as to maintain a pH of 6. Another problem with keeping traces in solution is that they often tend to develop mould. To combat this I use E202 Potassium Sorbate which is a yeast and mould inhibitor. Luckily the Potassium Sorbate works most effectively at a pH around 6 which is what the solution is kept at.
It is advisable to keep the solution away from light as it can cause the chelator to break down.

How do I make it?

It depends on how you dose to what quantities of each chemical you add. The important thing to remember is that you must get the right amounts of the macro's and trace's mixed up especially if you currently dose different amounts of the solutions. Also it might be an idea not to make the solution too concentrated. What I do to make life easy is to adjust the levels so that one full fill (25ml) of my old Tropica bottle is enough to dose the whole of my 200 litre tank in one go.

As an example here is a formulation that is based on my PMDD+PO4 formula:

10g  Potassium Nitrate
1.2g  Potassium Phosphate (monobasic)
4.0g  Potassium Sulphate
8.0g  Magnesium Sulphate Heptahydrate (Epsom Salts)
0.5g  E300 Ascorbic Acid
0.2g  E202 Potassium Sorbate
6g  EDTA Chelated Trace Elements Mix
500ml distilled water

If you wish to change the amounts of ingredients then as long as the levels aren't changed too much you can leave the amounts of Ascorbic Acid and Potassium Sorbate the same.

Dosing is 5ml per 40 litres
Each 5ml dose adds:
1.5 ppm Nitrate
0.2 ppm Phosphate
1.5 ppm Potassium
0.2 ppm Magnesium

DIY Tropica Plant Nutrition Plus

Tropica have very kindly provided an analysis of their product so with my calculator at the ready I have calculated a couple of matches. Tropica's TPN+ uses Ammonium Nitrate for it's source of Nitrogen, so I have copied this. The first formulation uses all Ammonium Nitrate and the second uses some Potassium Nitrate to replace the Potassium Sulphate which is used for the Potassium content. The third formulation replaces all the ammonium nitrate with potassium nitrate which results in higher Potassium levels.
Please remember that the first two formulations contain ammonium and so if you wish to use them please proceed with caution and test on a tank with no livestock in. I haven't tested them and are posted for information only.

DIY TPN+ (1)
3.8g Ammonium Nitrate
2.2g Potassium Phosphate (monobasic)
10g Potassium Sulphate
17g Magnesium Sulphate Heptahydrate (Epsom Salts)
0.5g E300 Ascorbic Acid
0.2g E202 Potassium Sorbate
5g EDTA Chelated Trace Elements Mix
500ml distilled water

DIY TPN+ (2)
2.9g Ammonium Nitrate
12g Potassium Nitrate
2.2g Potassium Phosphate (monobasic)
17g Magnesium Sulphate Heptahydrate (Epsom Salts)
0.5g E300 Ascorbic Acid
0.2g E202 Potassium Sorbate
5g EDTA Chelated Trace Elements Mix
500ml distilled water

DIY TPN+ (3)
48g Potassium Nitrate
2.2g Potassium Phosphate (monobasic)
17g Magnesium Sulphate Heptahydrate (Epsom Salts)
0.5g E300 Ascorbic Acid
0.2g E202 Potassium Sorbate
5g EDTA Chelated Trace Elements Mix
500ml distilled water

  TPN+ DIY TPN+ (1) DIY TPN+ (2) DIY TPN+ (3)
N 1.34% 1.34% 1.34% 1.34%
P 0.10% 0.10% 0.10% 0.10%
K 1.03% 1.03% 1.03% 3.89%
Mg 0.39% 0.39% 0.39% 0.39%
S 0.91% 0.82% 0.45% 0.45%
B 0.004% 0.01% 0.01% 0.01%
Cu 0.006% 0.002% 0.002% 0.002%
Fe 0.07% 0.08% 0.08% 0.08%
Mn 0.04% 0.02% 0.02% 0.02%
Mo 0.002% 0.002% 0.002% 0.002%
Zn 0.002% 0.01% 0.01% 0.01%

Tropica recommend to dose 5ml per 50 litres of tank water per week.
Following this each dose will add:

DIY TPN+ (1)
0.86ppm NH4
3.0ppm NO3
0.31ppm PO4
1.0ppm K
0.39ppm Mg

DIY TPN+ (2)
0.65ppm NH4
3.7ppm NO3
0.31ppm PO4
1.0ppm K
0.39ppm Mg

DIY TPN+ (3)
5.9ppm NO3
0.31ppm PO4
3.9ppm K
0.39ppm Mg

Final thoughts

I have mainly posted all of this for information for others. I am by no means 100% certain if what I'm doing is correct or safe for fish and plants but so far myself and many others haven't had any problems. The additives that are added are very commonly used in the food and drinks industry, so I'm presuming that they are safe for aquarium use. If you wish to use my methods then please do so at your own risk.

So far the solution has remained clear and bright and has had no settling out for up to six months. Plants still grow and pearl as before.

Most chelated trace mixes on the market contain Fe-EDTA and are brown in colour. This is because the type of iron used is ferric iron. Ferrous iron compounds tend to be green in colour. When making up the 'All In One' solution you may see that the solution turns green in colour over a period of a few hours. This is because ascorbic acid is able to reduce the ferric Fe-EDTA to ferrous Fe-EDTA. This is quite normal and nothing to worry about. In fact it might be of benefit as plants prefer ferrous iron to ferric iron.

In the UK you can buy the Ascorbic Acid and Potassium Sorbate quite cheaply from The Home Brew Shop and also sometimes on eBay.

The rest of the ingredients can be brought in the UK from or Fluidsensor Online and in the US from AquariumFertilizer. If you live in Canada then Rex Grigg will ship there.

This page was last updated 28th September 2009