Tropical Fish Forum
Tropical Fish Keeping Help and Advice => Fishtank Filtration and Cycling => Topic started by: Peterhill26 on February 16, 2018, 05:16:53 PM
-
Hi all is Crush Coral the same us Crush sand do they both raise your KH to put in a media bag to go in a external filter please
-
If the crushed coral and crushed sand are exactly what they say, yes they are both merely calcium carbonate in large gravel or sand sized chunks. They will dissolve slowly and raise GH, KH and pH. There will be a more noticeable effect if the pH is below 7.0 as calcium carbonate dissolves faster in acidic water.
If you can get it, crushed dolomite or dolomite sand is a better choice because this is calcium magnesium carbonate. GH is a measure of both calcium and magnesium together, so dolomite will make the added minerals more like those that occur in harder water in nature.
-
Although they're the same, you don't want to put coral sand in a filter because the filter will struggle to pull water through it. If you're putting it in a filter you want coral gravel.... or dolomite...
-
Good point, hampalong.
Can I ask why you need to increase KH? I have low KH at 3 degrees, and this doesn't cause any problems as long as I do large weekly water changes to replenish my KH. Don't forget that coral (or dolomite) will increase GH and pH as well, which might not be what your fish need,depending of course on what they are.
-
I have crushed coral in the internal filters of both my 125l community and 45l shrimp tanks. I use a muslin bag (from a Home Brew shop) to contain it. I had a ph crash whilst cycling the 125l, which I luckily caught before it stalled the cycle. This was the reason for eventually adding the coral. My tap water is kh 2-3, gh 3. The crushed coral has increased both to kh 4-5, gh 5. My tap and tank ph are 7.6 (both tanks). All measurements are with API liquid test kits, which I wouldn't be without!
Very occasionally, I detect a slightly reduced kh or gh. I correct this by adding a "mini" Aqualibra mineral block (Amazon). These contain various minerals and nutrients including calcium, magnesium, carbonate and bi-carbonate. My amano shrimps in the 125l are attracted to these. Each one "dissolves" in about 3 days.
Skittler
-
Out of interest, @Skittler - do you replace the crushed coral in your internal filters every so often or have you always kept the same crushed coral in it?
-
@fcmf It's been in there (125l) over 3 years - although I have added to it once to increase the effect. I simply rinse the muslin bag in old tank water at w/c. It sits on top of the white poly-pad, there is just enough space for it in my Juwel filter.
Skittler
-
Strictly speaking it should be under the white pad because that's first in the direction of water flow and is there to catch debris which will otherwise end up in the bag of coral ;)