It seems the alkalinity is slowly rising. It is now at 6.0 and the calcium is dropping - at 515.

Went to Exotic, and what did I do? I purchased some fish... Since the Ammonia/Nitrite levels were doing fine I assumed it would be fine to add some small fish. So I bought:

• 2 x small Percula Clownfish
• 1 x small Paracanthurus hepatus (Pacific Blue Tang)
• 1 x Pink Leather Coral
• 4 x Turbo Snails
• 4 x Red Legged Hermit Crabs
• 2 x Peppermint Shrimps
• 1 x Brown Brittle Star

When I got back home I saw an explosion of brown algae on the front side of the tank - on the live rock and on the substrate. I guess the white light, daylight, high phosphate levels and dKH buffer additions fueled them.

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.