Should I start dosing?

Nano Gabe · Feb 2, 2019

Hey guys so I’m a little confused of wether or not I should be dosing. I typically do water changes weekly when I get lazy like this last week bi weekly. I use fritz reef pro mix salt in my 28g biocube. It’s been 2 weeks since my last water change and I’ve been accumulating corals over time. I use the salifert test kits and when I checked my water today I had:
7.7 alkalinity
420 calcium
1350 magnesium
Now that’s a little low because fritz pro is suppose to be at 8.5 alk, 440 calcium and 1425 magnesium. But it’s been 2 weeks. I’m planing to change my water tomorrow in the evening. Also last night I got a red monti frag about 3inches which is relevant because I’ve heard SPS take up more calcium. So what do you guys recommend? should I start dosing? If so how would I go about figuring out how much to dose?

rkpetersen · Feb 2, 2019

You may or may not need to dose. Increased water changes might be sufficient.

But if you want to start dosing and to do it properly, the first step is to determine your daily alk consumption. Take an alkalinity measurement with as much precision as possible at a specific time of day, and record it. Maybe even repeat the test to be sure. Do no alk dosing. Test again at the same time the next day. And the day after that, and so on, if necessary. When you see a clearcut drop in alk, divide the drop amount by the number of days it took to get there and that gives you your alk level drop per day. If it's in dKH, multiply by 0.358 to get meq/l. Now figure out the water volume of your tank in liters. If you have 25 gallons, that's 95 liters. Multiply the meq/l number by the tank volume in liters number, and you have the total daily alk consumption of your tank in meq. All alk products give you their concentration in meq/l or meq/ml. Divide your total consumption in meq by the product concentration in meq/ml, and that's how many ml of the product you should add each day. You can give it as a single dose, but multiple doses is better. Also a good idea to start dosing a matching calcium product at the same ml volume per day. Dosing magnesium is less critical and can be done once or twice a week.