Treating dinoflagellates with kalkwasser dosing has been known for a long time but I've never seen a thread specifically outlining the necessary steps to the procedure. I have used this method for several years and have suggested it to dozens of other reefers always with 100% effectiveness. The few times it was not immediately effective it was always because the pH was not driven up aggressively enough. Once the pH was raised high enough in these tanks the dinos were brought under control.
Kalkwasser dosing is certainly risky and without taking certain precautions will certainly cause issues. I always recommend controlling the pH with an Apex or comparable controller but it is possible to do this without a controller. Also, once the dinos are gone it is sometimes necessary to continue the high pH indefinitely although many times the kalk dosing is stopped after 2-4 week with no recurrence of the dinos. Despite the risks it has turned out to be my go-to treatment. A few of the benefits to using kalkwasser is the minimal impact on the tank during treatment. I have increased pH from 8.0 to 8.8 in just a few days with no ill effects on coral or fish. Furthermore, blacking out the tank is not necessary so the corals do not suffer from lack of light.
If you are trying to figure out if you even have dinoflagellates you can use this method outlined in another thread:
Helpful Method to Identify Dinoflagellates
In order to document this kalkwasser treatment I intentionally stopped dosing kalkwasser to allow the critters to reinfest my reef aquarium. It ended up takin about 3-4 months for the dinos to grow to plague proportions. After the dinos became near overwhelming I started the kalkwasser dosing back up. I usually only need to maintain a pH of 8.3 to keep the dinos at bay but in order to treat them at this level a pH of 8.7 to 8.8 is needed.
We want to raise the pH about 0.1-0.2 per day until it has reached 8.6-8.8. This usually takes less than a week and the lights do not need to be turned off during treatment. Once the pH 8.6-8.8 keep it there for 2-4 weeks until the dinos have disappeared. In extreme cases (like my tank) you will need to siphon out the dinos and do a small water change. Remember, the dinos will go straight though any filter so you can not reuse the water, it needs to be disposed. Once the dinos are gone you can maintain a pH between 8.3-8.4 to keep the dinos in check. As stated above, some have completely stopped the kalk dosing without recurrence of dinos but usually the pH needs to stay elevated to prevent new outbreaks.
In my experience, the faster the pH is raised the more effective the treatment is. Despite this, I recommend taking it very slowly if this is the first time you’re using this method.
Day 1:
Siphone as many of the dinos out of your tank as possible and replace the water (do not filter the water). Add about 1.0 teaspoon of kalk per gallon of RODI top off water. This will typically bump up the pH about 0.1-0.3 after 24 hours.
Day 2:
After 24 hours your pH will hopefully be around 8.1-8.4. If your pH is already at 8.6-8.8 then maintain the same dosage. If it is not above 8.6 then increase the saturation to 1.5 teaspoons per gallon of RODI top off water. This will typically bump up the pH another 0.1-0.3 after 24 hours.
Day 3:
After 48 hours your pH will hopefully be around 8.2-8.5. If your pH is not 8.6 then increase the saturation to 2.0 teaspoons per gallon of RODI top off water. This will typically bump up the pH another 0.1-0.3 after 24 hours.
Day 4:
After 72 hours your pH will hopefully be around 8.3-8.6. If your pH is not at least 8.6 then increase the saturation to 2.5 teaspoons per gallon of RODI top off water. Now the kalk water is supersaturated so you will either need to manually shake it every hour or add a powerhead to the top water to keep the kalk suspended in the solution.
Day 5:
If your pH isn't up to at least 8.6 yet then you will need to increase the saturation to 3.0 teaspoons per gallon of RODI top off water. You will either need to manually shake it every hour or add a powerhead to the kalk water to keep the kalk suspended in the solution.
Maintain a pH of 8.6-8.8 for 2-4 weeks or until the dinoflagellates are gone. If the dinos are not mostly gone after 2 weeks you can siphon the remaining dinos out and replace the water. After the dinos are gone maintain a pH of 8.3-8.4. If you notice the dinos coming back increase the pH again until they disappear.
Notes:
- The limewater must be dripped into the tank continuously. It can never be dumped into the tank! Ideally you could use an Apex to dose the limewater. I do not recommend an ATO for this because if it malfunctions you will kill your coral and fish (I've learned this the hard way).
- Siphon as many dinos out before you start this treatment. You will need to dispose the water, straining the dinos through a filer sock and back into the tank will not work.
- A pH increase of 0.2 per 24 hours is typically considered very safe for your fish.
- You will ultimately need to raise the pH up to 8.6-8.8 (daytime) for about 2-4 weeks to kill the dinos. It's ok if the pH drops lower than that during the night.
- This is a rough guide, you really need to watch the tank closely to make sure the pH isn't rising too quickly.
- You might need to go above 3 tsp/gal of kalk, every tank is different.
- It is best to dose the display tank directly to prevent your skimmer and return pump from seizing up.
- Once you figure out how your tank responds to the kalk you can usually increase the kalk saturation faster depending on how fast your pH rises.
- Saturated kalkwasser is about 2 teaspoons per gallon
- You may need to turn off your calcium/alkalinity supplementation to prevent a spike in alkalinity. Monitor your alkalinity during treatment to make sure it remains stable
