Dosing of kalkwasser

[FuEl]

Hmm..just hope this does'nt sound stupid.....

Currently I'm topping up my evaporated water with saturated kalkwasser solely..I'm doing it via the drip method.

My evaporation rate is about 4-5 litres a day...so its about 4-5 litres of saturated kalk I am topping up into my tank daily...

Do I have to worry about

1)Calcium overdose?

2)pH swings with so much kalk top-up?

I understand that phosphate will be precipitated by kalkwasser as calcium phosphate. Will this remain in the tank and possibly be liberated later on? Or will it be inert?

Thanks for help peeps..really wish to get some things cleared up....

[BarraCudaTM]

how big is yr tank?

The concentration of Ca in kalkwasser is quite low and some will precipitate as well, It wont make a big difference if yr tank is >120g and the calcium intake is normal. Its still best to monitor yr Ca level before you drip until you know the Ca intake very well.

If you drip slowly over the day, the pH swing is minimal.

[IanJ]

Many people tend to drip kalkwasser overnight. This tends to counter the Ph drop that tends to occur then.

[bawater]

1) Do u need so much calcium? Its also not how much water u use- its how concentrated the kalk solution is. 1 teaspoon of kalk to the amount of water you use(1gal) should be fine as top off.

GET A TEST KIT and you can answer the calcium question of overdose.

i don't understand why you think you need a calcium supplement if you don't know what the initial levels are or what your target values are or if kalk alone is enough for your tank's consumption- this is the only way you can really overdose.

2)As ian has mentioned, just drip at night or early in the morning - as you tank's pH is highest during the day.

3)It has been proven that the long-term use of Kalkwasser precipitates phosphates out of the water and that these phosphate based compounds settle on and in the live rock in the aquarium, as well as in and on the substrate that may be present in the aquarium.

Since these compounds are not soluble at the high pH levels, they are really not a cause for concern, because in their insoluble state, they are not available as nutrients for uptake by micro algae and the growth of the same. Over time they simply accumulate more and more in the tank as insoluble matter; which can, by the way, be siphoned out from time to time (maybe every six months or so). Insoluble matter is of no concern, since it cannot affect tank conditions. In its insoluble state, it is also inert and does not react in any way with the water in the aquarium. In this state, it certainly cannot provide nutrients for algae to grow profusely in some reported cases.

BUT situations can, and may,occur whereby certain areas of the tank actually exhibit a different pH level than the one measured in the main body of water in the aquarium. In this instance, "different" means lower, and sometimes quite a bit lower, than the aquarium's pH level.

Phosphates that are bound in an insoluble form are, therefore, not available to algae. But can and will go into solution because of pH fluctuations in certain areas of the aquarium

This is brought on by the biological process - maybe decaying matter like fish food or a dead fish stuck in a dead space etc...

When pH drops in those areas of the aquarium, these insoluble compounds break up with the result that orthophosphate goes back into solution, giving rise to the sudden appearance of micro algae growth, a growth that was totally unexpected and unpredictable given the tank's water quality conditions.

PO4 absorbing media would be a better choice for permanent removal of phosphate. But don't worry so much about the phosphate part to stop you using kalk, its just one of those minor things.

[ervine]

But assuming you know your tank's calcium intake how then can one judge how much kalk to dose?

[bawater]

That is product specific - depending on the grade of kalk you use.

but to quote seachem's reef kalkwasser as a guideline:

Add 3 g (1 teaspoon) to 4 L (1 gallon) of water and mix to dissolve. If using pure water, a fully saturated solution is prepared by adding 6 g (2 teaspoons) to 4 L (1 gallon). Drip this solution into tank. Monitor pH and carbonate alkalinity. Adjust rate of addition to maintain a stable pH (8.3–8.4). HINTS: Adding 4 L (1 gallon) of a saturated kalkwasser solution to 150 L (40 gallons) will raise calcium by 24 mg/L. Always use the clear supernatant (top solution) only and do not allow undissolved material to enter the aquarium.

If you do not use the same brand, the above becomes a very rough guideline- but it still works.

This is also where u can use vinegar(in proper amounts) to get a higher concentration of calcium into the same amount of water thus not only being able to maintain calc. levels but also raise it over a few days depending on your uptake.

i think vinegar should be left till later , when you really know how much the tank uptake is and how much roughly you dose. anyway, its already been discussed in detail on previous posts.

[onghm]

HINTS: Adding 4 L (1 gallon) of a saturated kalkwasser solution to 150 L (40 gallons) will raise calcium by 24 mg/L.

Just to add on.

Using the reef chemistry calculator, you can also arrive at the amount of kalk to drip to get x amount of calcium and alk.

http://www.kademani.com/reefchem.htm

Keying in those figures in seachem's example yield the same result ; 1.1 gallon to raise 24ppm of calcium :-

volume : 150L

current cal : 400ppm

desired cal : 424 ppm

product : limewater (saturated)

product required : 1.1 gallons

Similarly, this should be used as a guide.

my 2 cents

[FuEl]

Ok..thanks bawater...will get a salifert one to find out exactly what's my calcium....

I have a sera one..but it consistently gives me values above 450ppm...time for the truth!