need the dosing gods

leemajors · May 6, 2015

how do you determine how much needs to be dosed in a tank

just say i check readings on monday when should i check again to determine my dosing needs
thx

im a newbie:squigglemouth:

Randy Holmes-Farley · May 6, 2015

Here's a copy and paste from another thread:

Supplementing in the early stages of a reef aquarium

1. Get an alkalinity test kit.
2. Measure your aquarium.
3. If the alkalinity is not below about 8 dKH (3 meq/L), and you are not already supplementing alkalinity, then you do not need to test for any other chemical (not counting salinity) and you do not need to supplement any chemicals at all.

The reason is that alkalinity will decline before anything else has significantly dropped, and if it has not dropped out of acceptable ranges, then neither will anything else have done so. :)

Monitor alkalinity for a few days before dosing so that you are not chasing random testing variations rather than actual tank decline in alkalinity.

JimWelsh · May 6, 2015

Leemajors, adding to what Randy said, I'd say do first learn how to use your Alkalinity test kit with reasonable precision (if you do the same test three times, you get three answers all pretty close to each other). Then, measure your tank's alkalinity (you might consider using the average of three tests in a row), and stop any dosing/water changes. Then, test for Alk daily, at more or less the same time each day. How long to monitor the drop depends a whole lot on how fast it drops. Just wait until you have a clear trend and consistent rate emerging from the data. Once you see such a trend, then take one last test (or the average of three last tests), and compute [DailyDrop] = ( [StartAlk] - [EndAlk] ) / [NumberOfDays]. Plug that into any of a number of online Reef Chemistry Calculators to determine your daily dosage rate for what you are dosing.

mike007 · May 6, 2015

What I would recommend Is getting your levels where you want them and then go 3 days without dosing and retest. Then retest and divide results by 3 that will tell you your daily consumption. Whether you are dosing manually or using a dosing pump then you can use the reef calculator to determine how much to dose each day to get parameters steady. Alkalinity and magnesium, calcium, should also be tested in this way.

beaslbob · May 7, 2015

leemajors said:
how do you determine how much needs to be dosed in a tank

just say i check readings on monday when should i check again to determine my dosing needs
thx

im a newbie:squigglemouth:

Best bet is to implement Dr. Randy's improved diy two part system.
With that system dose equal amounts of the calcium and alk solutions when KH drops down. then after using up a gallon of the cal and calk doses, dose 300ml of the magnesium.
my .02

Randy Holmes-Farley · May 7, 2015

This article of mine should also help:

The â€œHow Toâ€ Guide to Reef Aquarium Chemistry for Beginners Part 2: What Chemicals Must be Supplemented by Randy Holmes-Farley - Reefkeeping.com

hart24601 · May 7, 2015

I think Randy answered all the reef chemistry questions about 10 years ago and now just has to point us to the answers!

glb · May 7, 2015

Randy Holmes-Farley said:
Here's a copy and paste from another thread:

Supplementing in the early stages of a reef aquarium

1. Get an alkalinity test kit.
2. Measure your aquarium.
3. If the alkalinity is not below about 8 dKH (3 meq/L), and you are not already supplementing alkalinity, then you do not need to test for any other chemical (not counting salinity) and you do not need to supplement any chemicals at all.

The reason is that alkalinity will decline before anything else has significantly dropped, and if it has not dropped out of acceptable ranges, then neither will anything else have done so. :)

Monitor alkalinity for a few days before dosing so that you are not chasing random testing variations rather than actual tank decline in alkalinity.

Boy is this good news!

Gopi · May 7, 2015

So glad to read this...I was wondering the same thing!

hectat2 · May 8, 2015

Im new in the hobby. Questions is better use part a and b or only calcium and alkalinity and magnesium separate ?
If my alkalinity is good I don't have to test for calcium and magnesium just for my salinity?

Randy Holmes-Farley · May 8, 2015

hectat2 said:
Im new in the hobby. Questions is better use part a and b or only calcium and alkalinity and magnesium separate ?
If my alkalinity is good I don't have to test for calcium and magnesium just for my salinity?

Yes to the latter.

Using a two part system is better than independent additions, especially for a new aquarist. It is easier to keep things under control with such a system.

I compare methods here:

The Many Methods for Supplementing Calcium and Alkalinity - REEFEDITION