"Powderized" Crushed Coral to Raise KH?

[BisScottie Non-Ya]

I was wondering if it's possible to crush 'crushed coral' into a powder to increase surface area when trying to raise KH? I've had crushed coral in my tanks for a bit now and I can't seem to get my KH higher than a 2.

 

Has anyone tried to do this before and if  so, what was the result? Also I assume that the dosing would be much smaller?

 

I'd love to hear your thoughts on this,

-BisScottie

[Irene]

Hmm, never tried it before. I believe crushed coral works "faster" when you put it in a hang-on-back or canister filter so that water was constantly traveling through it. When I just put the crushed coral in a media bag in the tank (because I didn't want to use it as substrate), the effect on KH was much more gradual.

[TheDukeAnumber1]

I would look into aragonite, it's similar to crushed coral but sold as a sand sized substrate.

[Emika_B]

BisScottie - I’m in a similar boat with low KH.  All of my filtration is internal, so no hang-on-back for me.  However, I did modify a fluidized media filter to have a media bag of aragonite.  I figured that since there’s constant airflow through it it’d ‘disburse’ the benefits better than just plunking down a bag of it behind a chunk of wood.  So far there’s not been a change, but it’s early days.  You can see what I did in my 40 gallon planted journal.

Good luck!

[Mmiller2001]

Precision is better. Just buy some Potassium Carbonate (K2CO3) off amazon. It's dirt cheap. Then use https://rotalabutterfly.com/nutrient-calculator.php to calculate your dose.

[Kat_Rigel]

In theory, crushing the coral into smaller pieces with increase the surface area, and an increased surface area means more chances for it to dissolve (thats what you want in order to raise kH.) Just watch that you don't clog your filter.

[gardenman]

The advantage of coarser coral/aragonite is that it dissolves slowly and adjusts your parameters over time making it easier for the fish in your tank to adjust to the new parameters. If you go to a powdered form the dissolution will be faster and more abrupt. You'll have to add more on a regular basis as what you'd added before will be gone much more quickly than if you'd used a bigger, coarser form. If you miss a dosing or two you could find your tank going through some interesting swings that may not be ideal for the fish. Fish can adapt to pretty much anything if done gradually. Abrupt changes tend to be riskier.

[Hobbit]

Out of the tap my KH is 1. I have crushed oyster shell in all my tanks but I also add powdered limestone (calcium carbonate) in small doses directly to the water. You can buy it online for cheap. I dissolve a tiny bit in a jar and then add to my water from there. The powder is super fine and a little goes a loooong way! But for me the oyster shell and limestone is more for the calcium than KH.

For KH I honestly just use baking soda (sodium bicarbonate). I add a quarter teaspoon per 5 gallons when I do a water change. A lot of people think it’s too harsh for fish but as soon as it dissolves the bicarbonate turns to carbonate or carbonic acid depending on your pH. (i.e. it’s totally fine. 😉) You just have to experiment a bit to see how much baking soda to add to get the pH/KH you want.

Edited January 30, 2021 by Hobbit