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dirtknight9 wrote: ↑Wed Apr 02, 2025 5:15 pm Hey everyone,

I'm curious about dosing kalk (or Kalk+vinegar) in an LPS/Sof only tank - would it be effective? Or is it even necessary, or can I just rely on regular water changes?

Any thoughts on this?

Kalk isn't just for LPS though - it's an alkalinity and calcium supplement, so it'll help everything in the tank.

When it comes to carbon, it cleans your water chemistry and absorbs all the chemicals your corals produce when they're stressed. The thing is, carbon will keep absorbing until it's full, then it'll start releasing. That's why you need to change it every 2-3 weeks. GFO, on the other hand, absorbs nutrients in your tank, which helps prevent algae growth and lower nitrates. But be careful not to use too much GFO - it can lower nitrates too fast and hurt your corals. And if GFO particles get into the tank, they can kill inverts, so make sure to flush 2 gallons out every time you change them.

Thanks for the detailed explanation, flame9x. I now understand the role of Kalk and its benefits for my tank, not just LPS but all corals. I also appreciate the insight into GFO and carbon reactors, and the importance of monitoring their usage to avoid harming my corals. Your advice on dosing systems and skimmers is also well taken, I'll definitely consider investing in an automatic dosing system for the sake of reliability and convenience.

Also, would you recommend 2 part dosing over Kalk with my ATO setup, or does that not make a difference?

I think it's really a matter of personal preference. Once you get the hang of it, it's actually pretty straightforward.

Some folks swear by the simplicity of Kalk. Just mix it with your ATO, and you're good to go. Just make sure you've got a container that can hold enough for about a week. Of course, you'll still need to dose Magnesium separately, but that's not too big of a deal.

Personally, I think 2-part dosing is a breeze. I mix up a gallon of each chemical - calcium, magnesium, and alkalinity. It lasts me about six months, even with a 100-gallon tank. My Bubble Magnus doser takes care of the rest.

I've also started experimenting with supplement dosing, like Acro Power, and carbon dosing with vinegar. Now I've got five different things going into the tank, all managed by two dosers daisy-chained together.

Another thing to keep in mind is that dosing can temporarily affect your pH. When you're adding large amounts, it's best to break them up into multiple smaller doses to minimize the impact. This is actually another good reason to consider investing in an auto doser.

Another thing to consider with running Kalk through your ATO is that you've got two main limitations to keep in mind. Firstly, you're limited by evaporation - you can only add a fixed amount at full strength. While this might not be an issue for most LPS-dominant tanks, it can become a problem if you start keeping SPS.

Secondly, Kalkwasser is brutal on pumps. I'm talking about burning through peristaltic tubing or Aqualifter pumps at an alarming rate. I used to get about 6 months' life out of an ATO pump before needing a new one. In contrast, my peristaltic pumps have lasted 1.5 years with 2-part dosing and still work like new.

If I had to recommend a starting point, I'd say start with Kalk in your ATO, but be prepared to replace those pumps frequently - like, every 6 months or so. If you find yourself maxing out your dosage, you can then explore other options, such as switching to 2-part dosing, using a Kalk reactor to save your pumps, or even a calcium reactor.

I'm not a fan of Kalk, it's just too unpredictable for me. I'd recommend going with 2 part instead.

"Thanks for the info, I've decided to go with 2 part dosing, seems like the safer route.
So, to clarify, MAG and ALK need to be dosed separately and at different times, right?"

I think 2 part dosing is the way to go for heavy stocked tanks or those who are looking for more control, but for light to medium stocked tanks, I believe Kalk is the way to go. It's super cheap and allows you to dose CA and ALK in one process, while also giving your pH a boost - which is something I need, given my low pH levels.

Now, I know some of you might be thinking, "Kalk is a pain to tune in, especially when using it in your ATO water." And yeah, it can be. You have to adjust the amount of Kalk powder you put in the water, and if you add too much or need to add more Kalk powder, it can be easy to lose track of how much you need to add in the future to maintain proper saturation.

For me, the solution was to dose saturated Kalk. I find it way easier to adjust the amount of saturated Kalk going into the tank by adjusting the time, rather than trying to adjust the saturation of the ATO water.

My setup is pretty simple - I use pure RO/DI water for my ATO, and to maintain proper CA/Alk levels and boost my pH, I adjust the amount of Kalk I dose. Right now, I'm dosing 40 seconds of saturated Kalk per hour, and with my level of evaporation, I've got a lot of room to play with before I max out my Kalk levels and need to add 2 part dosing on top.

If you're interested in learning more about Kalk dosing, I highly recommend checking out these Bulk Reef Supply videos - they're super informative and have helped me get my Kalk dosing dialed in: https://www.youtube.com/watch?v=bVI69xOb_JM, https://www.youtube.com/watch?v=EwyH5LQ1tsk, https://www.youtube.com/watch?v=fCnqAnn0yxo.

dirtknight9 wrote: ↑Wed Apr 02, 2025 5:15 pm Hey everyone,

I'm curious about dosing kalk (or Kalk+vinegar) in an LPS/Sof only tank - would it be effective? Or is it even necessary, or can I just rely on regular water changes?

Any thoughts on this?

With 2 part dosing, each chemical needs to be dosed separately, that's the key. Many people only dose calcium and alkalinity via pumps, and then add magnesium on a monthly schedule, it's pretty common.

When I say they need to be dosed separately, I mean it - the chemicals must be kept separate before use, and should not be added in the tank at the same time or same location. If you mix them, they'll precipitate out, and that's not what you want.