Since Alkalinity, Calcium and pH all need to be balanced, I bought a Calcium test kit. The Calcium seems to be at 545mg/l! That is very high. Since my Alkalinity is only 7.0 dKH, I decided to make use of Kent Marine’s Pro Buffer dKH. I started adding 35ml to the water daily. I also stopped adding kalkwasser. The idea is that since kalkwasser is a balanced supplement, I first need to get the proportion of Calcium and Alkalinity right then I’ll resume adding kalkwasser. I think the different salt I used as well as the RO water to fix SG messed up the balance.

Did the first accurate measurement of Ammonia myself and found that Ammonia is < 0.01mg/l, Nitrite is 0.20mg/l and Nitrate is 10mg/l. Since the Alkalinity dropped severely to 5.0 dKH, I decided to open up the tank so that evaporation is increased. In one hour the topup pump came on about 6 times. Since this was quite severe I closed down the lids of the aquarium.

The RO water mixed with Kalkwasser is BAD since it reacts quickly with air to precipitate the calcium out of the solution, and pumping in the precipitate is A Bad Thing.

So I put a Tunze Calcium Dispenser in the RO bucket. Basically the RO water is pumped through the dispenser to the sump. Inside the closed dispenser is the kalkwasser mix.

Added 10ml Combisan and will try to add this on a weekly basis.

Steven tested the water and it seems to have almost no Ammonia/Nitrites. So he said it should be fine for me to add some invertebrates. Thus I purchased the following:

• Colt Coral
• Green Mushroom Coral
• LPS Brain Coral (came on the same rock than Green Mushroom Coral)
• Boxer Shrimp
• 4 Turbo Snails
• 4 Blue Legged Hermit Crabs

I replaced about 30l of saltwater with fresh RO water to fix the SG. It is now 1.025 which seem much better. The alkalinity is taking a dip though - down from 7.5 to 6. Started adding kalkwasser again by adding 4 flat teaspoons to 13l of RO topup water. This implies I have just installed a Tunze Osmolator kit that handles auto topoff.