Reef tank dkh

Acemann · Jun 21, 2023

Hey so I doubt anyone will know the answer to this question but there is a way to make your own reef rocks using a concrete mixture and and curing it in fresh water for over 3 months and I did that over a year ago and people have been saying that it could effect your reef tanks water acidity. I’ve had my reef tank up and running with fish and coral in it for about 8ish months and I’ve always had the problem with my carbonate hardness I’m not sure if it is just my testing maybe it could be outdated or something? Anyway everything seems to be healthy and the rest of my water parameters are pretty good I’d say. Here are my parameters.
I have a 100 g acrylic tank with a 50 g sump, 1 radion xr15 pro 2 coralife 30inch light strips,
2 clownfish,
1 cotton candy torch coral,
1 purple tip frogspawn,
Kenya tree,
Xenia,
Zoas ,
And some invertebrates.
Salinity: 1.025
Calcium: 400 ppm
Phosphate: 0-0.25 ppm
Nitrate:10 ppm (about to do a water change)
Dkh: 15???
Also I have been getting a lot of algae.

Randy Holmes-Farley · Jun 21, 2023

Cement based rocks may be an ongoing source of alk, yes, but so can other sources, such as tap water, declining or dosing nitrate, and very slow dissolution of rock and sand down in pores where the pH is low.

Are you using a low alk salt mix for water changes?

Acemann · Jun 21, 2023

Randy Holmes-Farley said:
Cement based rocks may be an ongoing source of alk, yes, but so can other sources, such as tap water, declining or dosing nitrate, and very slow dissolution of rock and sand down in pores where the pH is low.

Are you using a low alk salt mix for water changes?

I use an ro/di water filter for my instant ocean reef crystals mix. When I was first starting my tank I made the mistake of dosing nitrates just because it was at 0 for over a month. I am unaware that they had low alk salt mix. What brand would you suggest?

Randy Holmes-Farley · Jun 22, 2023

Acemann said:
I use an ro/di water filter for my instant ocean reef crystals mix. When I was first starting my tank I made the mistake of dosing nitrates just because it was at 0 for over a month. I am unaware that they had low alk salt mix. What brand would you suggest?

You can easily drop the alk in any high alk mix, or you can use something like the Red Sea blue bucket or Tropic Marin pro.