View Full Version : Do you have to dose a tank if you do weekly water changes?

09/25/2017, 05:36 PM
Just curious about this, I have never dosed a tank before and was wondering if its something you have to do even if you do weekly water changes? I do about 30% water changes every Thursday. Is it true if you do weekly water changes all of the trace elements are restored? Or is dosing a must? Also what is kalkwasser and how does that work?

Reef Bass
09/25/2017, 05:48 PM
Your need to dose is determined by the types and quantities of corals you keep. If you have few stony corals, likely water changes will take care of restoring levels of key compounds.

If you're not sure, test. When you notice water changes not keeping levels where they need to be, consider dosing. I like stony corals and dose alkalinity, calcium and magnesium solutions with dosing pumps on a controller.

09/25/2017, 05:56 PM
What alk or khb are best to maintain? After a water change mine will usually be 9 khb and dwindle to 7 before a water change. Does fluctuating between 7 and 9 in a week cause problems?

09/25/2017, 07:33 PM
There are no absolutes in this hobby.
This is why we test. Test your water and you will have your answer.

But typically, once you've got coral in the tank and they are growing, you will need to dose alkalinity and calcium, and sometimes magnesium. Your water changes should go a long way towards replacing the minor trace elements.

09/26/2017, 04:43 AM
You need to dose when your current water change schedule is not keeping the levels you choose to maintain stable enough.. plain and simple..

I personally would not allow a 2dkh swing per week.. 1 yes.. 2 no..
So you either increase water changes or start dosing or live with that swing..

09/26/2017, 04:44 AM
Does fluctuating between 7 and 9 in a week cause problems?

It's hard to answer that because it'll depend on the specific corals and other conditions in the tank. It's not a black and white thing. Most people, especially those with more delicate corals, would consider that to be a fairly large swing. If your livestock is healthy and growing, don't worry about it.

I like stony corals

Based on this comment earlier, I wanted to point out that coral type doesn't always have as straightforward a relationship to calcium and alkalinity consumption as people sometimes think. I've had tanks full of healthy, growing softies (and coralline algae) that sucked the parameters down just as fast as stony corals - many softies use quite a bit of minerals to build the sclerites in their tissue that help give them shape and structure.

09/26/2017, 05:51 PM
coralline algae alone will suck down alk/cal/mag.....don't be afraid of dosing, it will be in your future eventually. study up on it now so you'll be ready for it when it's needed