Lowering Alkalinity

vic5hands · Nov 13, 2015

Calcium 425
Alk 14
Mag 1400

Running MTC mini calcium reactor e fluent set to 6.4 to 6.7
Apex Controlled.
Bio pellet reactor
Carbon reactor
Phosphate reactor
210 gallon full stocked with SPS
Some LPS.
Reef Octopus 3000ex skimmer
Salinity 35
PH. 8.2
Temp 79
Corals bright fully extended
Water change every 15 days . 50 gallons. Still with water change same readings.
Using Kent Reef Salt Mix
Don't understand why it so high.
Help

JimWelsh · Nov 13, 2015

How are you testing for alkalinity? Have you tested your new made ASW, and what does it say? It could be testing error.

Zacco · Nov 14, 2015

As stated above, I would test your new batch water before adding it to the tank. If it is at acceptable levels, I would have to suspect a problem within your Reactors. Alk will come down on its own as it is it used up by the corals if you dont dose any type of alk buffer. Don't add any type of Alkalinity, Lime water (Kalkwasser), or a Calcium Carbonate/Carbon Dioxide Reactor if your Alk. is already high.

Randy Holmes-Farley · Nov 14, 2015

I would presume your CaCO3/CO2 reactor is just delivering too much calcium and alkalinity.

I'd turn off the CO2 and let the alk decline, then restart with the pH inside set higher (say, 6.7 for the turn on, then adjust from there as needed).

Zacco · Nov 14, 2015

If you are still stumped by your problem, check your salt mix or change brands. Something to keep in mind: Borate. Borate appears naturally in sea water and will probably be present in salt mixes.Excessive amounts of Borate added to salt mixes will contribute to a significant portion of your tanks alkalinity. This will give you an Alkalinity reading that doesn't reflect the true amount of carbonate and bicarbonate in the water. It is best to use salt mixes that better mimic the qualities of sea water. Some companies intentionally or unintentionally add Borate to their mixes, adding more than 10 times the natural amount. If your Kent Reef salt mix has a batch analysis on the bag or tub, I would check those readings. Maybe Randy can chime in on this. I do not claim to be an expert on Borate and it's effects on Alkalinity.