IFC Aquarium Fertilizer Calculator

[plantypus]

Thanks @Zeus. much appreciated.

I will mix up my first macro solution today and will start using it from tomorrow.

I now have 2 more questions:

1. I have purchased some small plastic dipping sauce pots to measure and store the Magnesium Sulphate and Calcium Chloride in order to make dosing easy and avoid measuring up every time I do a water change. Can I store both dry salts in the same pot or do I need to store them in separate pots? I'm not sure whether the chemicals will react while in their solid state or even if they're too close together when I'm adding them to the tank.

2. I will be using Solufeed Sodium Free TEC for the micro nutrients. Is there a benefit in creating a water based solution or can I just dry dose this? For my 210 litre tank I only need to add about 0.3 grams every other day.

Many thanks!

 

[John q]

2. I will be using Solufeed Sodium Free TEC for the micro nutrients. Is there a benefit in creating a water based solution or can I just dry dose this? For my 210 litre tank I only need to add about 0.3 grams every other day.

Yes, there's a big benefit to doing this.

Micro mixes like this are generally mixed up in big batches to ensure you get an even distribution of all the nutrients; Eg if you analysed 1kg of this product the chances are the percentages of each individual nutrient would reflect what's written on the box, in contrast if you repeated the same analysis on 3300 individual 0.3g scoops each scoop would likely differ.
Think of it like mixing 500g of brown rice with 500g of white rice and then measuring out 0.3 g, what's the chances we'd get a perfectly equal brown to white grain ratio each time? Crap analogy, but you get the idea.

So basically the more you mix in a solution helps ensure you are adding what you think, rather than guessing. I'd also imagine weighing 0.3g every other day would soon become tiresome.

Haven't double checked the maths but think 15g of the micro blend in 500ml of water, each 10ml dose should yield equivalent to dry dosing 0.3g.

 

[dw1305]

Hi all

....... I have purchased some small plastic dipping sauce pots to measure and store the Magnesium Sulphate and Calcium Chloride in order to make dosing easy and avoid measuring up every time I do a water change. Can I store both dry salts in the same pot or do I need to store them in separate pots? I'm not sure whether the chemicals will react while in their solid state or even if they're too close together when I'm adding them to the tank....

The chemicals are inert while they are dry but you may have an issue with calcium chloride (CaCl2.nH2O), because it is deliquescent and will pick up moisture from the atmosphere. That could lead to your dry dosing being a single solid lump rather than two separate salts. This lump should eventually go into solution in the tank, even any (scarcely soluble) CaSO4.2H2O.

Personally I wouldn't care, but I have a pretty slap dash approach to dosing.

Cheers Darrel

 

[simon_the_plant_nerd]

Hi all

The chemicals are inert while they are dry but you may have an issue with calcium chloride (CaCl2.nH2O), because it is deliquescent and will pick up moisture from the atmosphere. That could lead to your dry dosing being a single solid lump rather than two separate salts. This lump should eventually go into solution in the tank, even any (scarcely soluble) CaSO4.2H2O.

Personally I wouldn't care, but I have a pretty slap dash approach to dosing.

Cheers Darrel

Hi Darrel.

I read on one of your posts a while back that all CaCl2 becomes the hexahydrate form because of its deliquescence. As such, I’ve treated my calcium chloride as that form. It’s stored in my shed in an ice cream tub. Is there any reason to treat it otherwise when I’m using it to remineralise my (very soft) tap water? It was bought as the dihydrate hemihydrate form I believe.

Cheers.

 

[MichaelJ]

have an issue with calcium chloride (CaCl2.nH2O), because it is deliquescent and will pick up moisture from the atmosphere.

Yes, calcium chloride is highly hygroscopic - one of the most hygroscopic compounds actually - why its frequently used in dehumidifier products. Which means we could potentially end up adding much less Calcium by weight that we think we are adding, because of the weight increase by the moisture, if it's not stored and handled properly. Generally speaking, especially with anything containing chloride, it's imperative we store it it in a hermetically sealed container and preferably only handle it in a dry environment.

Personally I don't use any Chloride based dry salts. Cl is a trace element our tanks wont benefit from in abundance, but it's often our only option if we want to pre-batch our fertilizers due to the higher solubility.

Cheers,
Michael

 

[Hanuman]

[...] Can I store both dry salts in the same pot

Although possible, I wouldn't. As Micheal and Darrel said, CaCl is highly hydroscopic. You would end up measuring erroneous amounts of both salts with time.
In fact my CaCl would probably need a reheating because as of now, half the weight (and probably more) is water. If you have a hermetically sealed container that would be the best way to keep CaCl, else, keep it in a ziplock bag and then put the bag in whatever container you can find. This is to minimize CaCl absorbing water with time.

Read here and here.

2. I will be using Solufeed Sodium Free TEC for the micro nutrients. [...] can I just dry dose this? For my 210 litre tank I only need to add about 0.3 grams every other day.

Personally I think that's a bad idea. Better to prepare a solution. John explained it well. Plus it's less cumbersome to dose a liquid every other day than to weigh 0.3gr. Finally, unless you have an analytical scale, weighing 0.3g on a cheap commercial scale will result in additional inaccuracies.

Haven't double checked the maths but think 15g of the micro blend in 500ml of water, each 10ml dose should yield equivalent to dry dosing 0.3g.

Checked it with the IFC calculator. That is correct. Dosed 4 times a week should achieve a 0.5ppm Fe level in the tank.

 

[simon_the_plant_nerd]

Hi @MichaelJ @Hanuman.

Did either of you see my question above about CaCl Hexahydrate? I aimed it at @dw1305 but perhaps you know the answer too? I just want to get my calculations correct.

Thanks.

 

[Hanuman]

Hi Darrel.

I read on one of your posts a while back that all CaCl2 becomes the hexahydrate form because of its deliquescence. As such, I’ve treated my calcium chloride as that form. It’s stored in my shed in an ice cream tub. Is there any reason to treat it otherwise when I’m using it to remineralise my (very soft) tap water? It was bought as the dihydrate hemihydrate form I believe.

Cheers.

I suppose that eventually it will reach a state of equilibrium where no more water will be absorbed. You could treated it as an hexahydrate if you are not so anxious about how many Ca ppm go into your tank. One thing is for sure though, if you have dosed the same amount for months/years in your tank the Ca content in your tank has decreased but probably not to a point where it's a problem else you would have noticed.

Else you could heat it up at low heat in a pan/pot untill you see it turn white like chalk and becomes powdery. It will return back to its anhydrous state. Then keep it in an airtight container to minimize water absorption. You should redo your calculation again since the Ca content per weight will be higher in the anyhdrous state.

 

[simon_the_plant_nerd]

I suppose that eventually it will reach a state of equilibrium where no more water will be absorbed. You could treated it as an hexahydrate if you are not so anxious about how many Ca ppm go into your tank. One thing is for sure though, if you have dosed the same amount for months/years in your tank the Ca content in your tank has decreased but probably not to a point where it's a problem else you would have noticed.

Else you could heat it up at low heat in a pan/pot untill you see it turn white like chalk and becomes powdery. It will return back to its anhydrous state. Then keep it in an airtight container to minimize water absorption. You should redo your calculation again since the Ca content per weight will be higher in the anyhdrous state.

Thanks.

It’s not been in storage long and it’s still in flakes form. I’d rather be adding a bit more calcium than a bit less. I’m only raising my GH to 5 or 6 and some of that comes from MgSO4. It’s just for my invertebrates and I dose at water change (35% twice weekly). I also dose trace and iron with my ferts so I just want to ensure I’m keeping the water stable.

I’m starting a shrimp only tank soon which will be ran at a higher level of calcium and magnesium so my only concern there is to ensure my calcium level is enough. I’m not too worried about it being a bit higher.

 

[Hanuman]

If you want to maintain a more stable Ca content in your water then using CaSO4 is probably your best friend as it will not absorb as much water as CaCl2.

 

[Andy Pierce]

Just on the chemistry piece, you could consider calcium nitrate which is soluble in water and where the stable tetrahydrate form is generally available (Calcium Nitrate Tetrahydrate 99-102.0% ACS). For EI dosing you'd be looking to add nitrate anyway.

 

[Hanuman]

Just on the chemistry piece, you could consider calcium nitrate which is soluble in water and where the stable tetrahydrate form is generally available (Calcium Nitrate Tetrahydrate 99-102.0% ACS). For EI dosing you'd be looking to add nitrate anyway.

I am not sure that's the best strategy to remineralize water. Ca(NO₃)₂ will add more nitrate than Calcium (3 times more in fact) and I would assume that the nitrate is already being taken care by the main fertilizer/macro side. It is an option though if no other compounds are available but it would need to be added separatly from other compounds.

 

[MichaelJ]

I am not sure that's the best strategy to remineralize water. Ca(NO₃)₂ will add more nitrate than Calcium (3 times more in fact) and I would assume that the nitrate is already being taken care by the main fertilizer/macro side. It is an option though if no other compounds are available but it would need to be added separatly from other compounds.

Yes. Unless you're targeting very low levels of Ca with the CaNO3 you will get a huge amount NO3. For NO3 I am actually using MgNO3. In one of my low-tech tanks I do my RO remineralization and macro front-loading (all from dry salts) for the whole two week duration of the WC cycle which gives me a bit more flexibility to mix and match compounds. I use MgSO4 and CaSO4 for remineralization and opted for MgNO3 for my NO3 which allows me to use less MgSO4 and thus slightly lowering my SO4 level (S really). I could have used CaNO3 but MgNO3 was easier to find at the time I was shopping for it. Otherwise I don't think there is a benefit from using MgNO3 over CaNO3... it will reduce the SO4 footprint equally for the same amount of NO3 and targets of Ca and Mg when using the SO4 based compounds.

Cheers,
Michael

 

[plantypus]

Yes, there's a big benefit to doing this.

Micro mixes like this are generally mixed up in big batches to ensure you get an even distribution of all the nutrients; Eg if you analysed 1kg of this product the chances are the percentages of each individual nutrient would reflect what's written on the box, in contrast if you repeated the same analysis on 3300 individual 0.3g scoops each scoop would likely differ.
Think of it like mixing 500g of brown rice with 500g of white rice and then measuring out 0.3 g, what's the chances we'd get a perfectly equal brown to white grain ratio each time? Crap analogy, but you get the idea.

So basically the more you mix in a solution helps ensure you are adding what you think, rather than guessing. I'd also imagine weighing 0.3g every other day would soon become tiresome.

Haven't double checked the maths but think 15g of the micro blend in 500ml of water, each 10ml dose should yield equivalent to dry dosing 0.3g.

That's a great point @John q , it really makes sense, many thanks for pointing that out!
I was planning on mixing the solutions a few weeks ago but had to do some urgent work that stopped me from doing so. I will have a go at it this weekend.
I purchased from Ikea some big 10Lt air tight containers and some smaller 0.6Lt to put inside the big ones to store all the dry salts and after 3 weeks of being left there they appear to be uneffected by humidity as far as I can tell (i.e. still granular and no big lumps). CaCl is nicely separated in flakes. Read a little bit online about drying it out but doesn't sound too straight forward so I will just measure 50% extra as @dw1305 suggested.
Will report back when all is ready mixed and used a few times.

 

[plantypus]

Although possible, I wouldn't. As Micheal and Darrel said, CaCl is highly hydroscopic. You would end up measuring erroneous amounts of both salts with time.

I think I failed to explain it well. The bulk dry salts are stored separately in air tight containers. I got some tiny pots (1oz) that will just about hold 12.28 grams of Magnesium Sulphate and 10.08 grams of Calcium Chloride. I can measure up both dry salts and fill those tiny 10 pots so then I can just tip them into the tank every time I do a water change and avoid opening the big tubs/bags with the dry salts every week.

If, as @dw1305 says, the chemicals are inert while they are dry then it should hopefully work.

Sorry for the confusion.