Calcium

[wolfiewill]

Does anyone dose calcium? I'm moving to dry fertilizers and have a source for everything but calcium. I'm going to use Equilibrium as a basic source but wanted to top up the calcium concentration a bit.

[exv152]

Look into calcium sulfate CaSO4, or calcium carbonate CaCO3, but equilibrium should have enough Ca for your plants.

[fischkopp]

I have been supplementing Calcium with Calcium Sulphate for years now. Equilibrium works too, but it's mostly potassium. This is fine for smaller tanks, but if you want to raise Calcium levels seriously (and cost concious) in a bigger tank, you want to supplement it individually. I got pretty got results with CaSO4, pogostemon helferi and rotalas seem to respond very quickly to increased Ca levels.

The only place I found CaSO4 locally was DeFalco. They sell it as a supplement for beer making.

Good luck!

[fischkopp]

When dosing my tank in the morning I realized that I am also adding calcium another way: Calcium Nitrate!

I am dosing half potassium nitrate and half calcium nitrate at least twice a week. It's probably a good idea to add potassium sulphate as well when doing that so that potassium isn't running low.You will have to experiment with your tank to see what's required.

[exv152]

BTW, in my search for a good source of micro nutrients online (plantex CSM+B), I found calcium chloride CaCl2 can be used too.

[exv152]

I just got back from B&B and they're now selling calcium nitrate.

[wolfiewill]

Thanks, everyone. I' got some CaCO3 from a beer making kit. I think I'll give it a try.

[alexv]

Thanks, everyone. I' got some CaCO3 from a beer making kit. I think I'll give it a try.

Hmm, are you sure it's CaCO3? Because it's a general chalk and it doesn't dissolve in water much... Are you sure you are not using Ca(HCO3)2 instead? Just curious....

And yes, I used CaCl2 before (from B&B). Good to know they are now selling nitrate too...

[exv152]

Calcium carbonate (percipitated chalk) does work, I've tried it and it is true, it doesn't disolve as well as calcium nitrate or chloride. The up side is it boosts GH and KH at the same time, but use it very sparingly. I noticed they're selling magnesium sulfate and potassium sulfate, for those into dosing PPS.

[wolfiewill]

Hmm, are you sure it's CaCO3? Because it's a general chalk and it doesn't dissolve in water much... Are you sure you are not using Ca(HCO3)2 instead? Just curious....

It says CaCO3, and it's from a chemist shop. So I'm sure it is. I'll try it soon and report back.

[angelcraze]

I am interested in adding calcium for not only my plants, but snail shells.  Although there is no problem, I know they require this.  I am using equalibrium for now, but want to add more,  I am afraid of raising the ph too much though, cause I have congo tetras in this tank.  Maybe I'll try calcium nitrate.

[wolfiewill]

I just started using CaNO2 (from B&B Hydroponics) in a small planted only tank instead of KNO3 at a nitrogen source. It's very water soluble and probably changes the pH only slightly. I say that because I'm not really sure as I've just started the tank up last week, and don't know what the baseline pH would be with KNO3.

However, GH and KH are higher. I used the 'Fertilator' to obtain optimum levels for all ferts in conjunction with calcium and magnesium; and after including Epsom salts, Equilibrium and KH2PO4 (the substrate is Fluorite), the GH and KH are 7 and 3 respectively. I'm stoking the CO2 way up and have a pH of 6.1.

The result is that I'm getting pearling on Java fern, the only plant I've got in that tank.

[exv152]

A combination of KNO3 and Ca(NO3)2 is probably a good idea, you'll probably run out of potassium quicker than Ca by going exclusively with Ca(NO3)2 as a nitrate source.

[wolfiewill]

A combination of KNO3 and Ca(NO3)2 is probably a good idea, you'll probably run out of potassium quicker than Ca by going exclusively with Ca(NO3)2 as a nitrate source.

Ok. Good idea. So I'm dosing calcium nitrate just after a major water change and measuring the change in GH compared to my other tanks in which I only dose KNO3. After that I dose KNO3 only. I'll wait to see over time if the GH drops, presumably because the Ca is being used up (it went up to 8 dGH) before adding more. If the GH doesn't drop then Ca is probably not deficient. Sound right?

I use the 'fertilator' to calculate my dosing for a target appropriate to the Redfield ratio, and keep the GH in the 4-6 range; and to get the suggested Ca and N on one dose I can't add more K or I'm beyond the suggested range. The NO3 should be consumed and so I'll add KNO3 as the only source of N in subsequent doses. What do you think?

[alexv]

A combination of KNO3 and Ca(NO3)2 is probably a good idea, you'll probably run out of potassium quicker than Ca by going exclusively with Ca(NO3)2 as a nitrate source.

Just a warning, do not mix Ca(NO3)2 and K2SO4 together in the same solution, unless you want a lot of white stuff (CaSO4) precipitating from the water column Been there done that...

[wolfiewill]

Just a warning, do not mix Ca(NO3)2 and K2SO4 together in the same solution, unless you want a lot of white stuff (CaSO4) precipitating from the water column Been there done that...

OOO... ok. I'd never thought of that. And I was going to try an all in one solution at some point too.

By the way, alexv, what kind of dosing equipment do you have? I think I want one for my large tank. Can't let the hired help dose while I'm on vacation, eh.

[alexv]

OOO... ok. I'd never thought of that. And I was going to try an all in one solution at some point too.

By the way, alexv, what kind of dosing equipment do you have? I think I want one for my large tank. Can't let the hired help dose while I'm on vacation, eh.

I'll show you when you come over for PA meeting