Reef Aquarium Additives FAQs - What To Dose, How Much, and When!
Maintaining water chemistry is one of the more complicated aspects of keeping a reef aquarium but then again, it really is pretty straightforward so long as you don't overcomplicate things with too many additives.
Keep in mind that these answers are geared for reef aquarists in that 1-2 year range in terms of experience. If you're looking for more detailed information, browse the Additives & Water Chemistry category of the BRS Learning Center for all kinds of in-depth videos and additional information. We also have a full staff of experienced reef aquarists available in our Customer Service Center that are happy to answer your questions.
What does "dosing" mean?
The term "dosing" is how we describe the action of using additives in your reef aquarium. Simply put, it means your adding liquid solutions into your aquarium in measured amounts. We typically dose to maintain water chemistry but is also done to add nutrition, add bacteria, or remedy certain problems.
Doesn't a weekly water change supply everything my corals need?
Yes, but this won't last long. As you add more corals and those corals grow larger, they will consume more and more elements, eventually overcoming what your weekly water change can replenish. Once you have reached the point at which you're noticing your calcium and alkalinity levels are dropping in between water changes, it's time to start using additives. This usually coincides with the addition of stony corals.
Different corals absorb different elements at different rates. Stony corals that contain a rigid skeleton (SPS and LPS) are going to uptake calcium, alkalinity, magnesium as well as a variety of minor and trace elements. Soft corals on the other hand do not uptake calcium and alkalinity but do uptake certain minor and trace elements. The exact elements and the rate at which they are used vary between different coral species and therefore, change from tank to tank.
Do I need to dose minor and trace elements?
The goal in a reef tank is to achieve the most stable conditions possible which means holding constant levels of all the elements like what is found in natural seawater. As corals grow, they primarily uptake calcium, alkalinity, and magnesium which are the major elements, the most important elements you will need to dose.
Minor and trace elements are also used by corals but at much slower rates and will only require dosing in medium to heavy demand aquariums. Most reef tanks can sustain the necessary trace elements via a weekly water change for the first 12 months. As your tank matures, there are minor and trace element solutions that can be integrated into your regular dosing routine.
What about dosing magnesium?
Magnesium is considered to be a major element but is not used up as fast as calcium and alkalinity. If you're not maintaining magnesium daily alongside calcium and alkalinity, you can typically get away with doing it only once per week.
What is a Two-Part (2 part) Solution?
"2 Part Solution" is a broad term we use to reference an additive approach that contains two ionically balanced solutions, one solution maintains calcium and the other maintains alkalinity. The ionic balance part is important because when dosed correctly, they will maintain the perfect balance of calcium and alkalinity in your reef.
Some two-part solutions contain magnesium and trace elements (bonus!) while others recommend separate magnesium and trace element solutions. While a two part-solution still remains to be the most affordable option for dosing a reef tank, we now also have access to one-part solutions such as Tropic Marine All-For-Reef which maintains everything using a single solution.
How do I choose the right additives?
While there are a variety of options, the best advice we can give you is to share what we find to be the best options for those of you within the 1 - 2 year range.
One or two-part solutions are the most popular because they are easy to dial in the right dosage and generally affordable. We organized our best-selling additives below where the Beginner Additives are best used on low-medium demand tanks and the Advanced Additives are appropriate for mature aquariums with a heavier demand for calcium and alkalinity.
Additives For Beginners
Tropic Marine All-For-Reef
The best one-part additive system that maintains all major, minor, and trace elements in your reef tank. Best used on smaller aquariums less than 50 gallons with a low-medium demand. While there is a more economical powder version, it still can be a little expensive when used on larger aquariums with a heavy demand for calcium and alkalinity.
BRS 2-Part Pharma
The most affordable two-part solution on the market plus a magnesium solution to keep your magnesium levels balanced. Simply mix with RO/DI water and use our handy Reef Calculator to determine how much you need to dose. The starter kit includes mixing jugs, measuring cups, and pump tops to make manual dosing easy.
One of the original two-part solutions that is designed to maintain magnesium and select trace elements along with calcium and alkalinity. Both solutions are dosed in equal amounts daily to maintain stable parameters in your reef tank. Most effective on low-medium demand aquariums.
ATI Essentials Pro
ATO Essentials is beneficial because it maintains calcium, alkalinity, and magnesium and also contains 25 additional trace elements that are required for coral growth.
Brightwell Aquatics Reef Code
Brightwell Aquatics' two-part solution maintains both calcium and alkalinity at a balanced ratio. It is available in both a liquid and powdered option but does not contain magnesium which should be maintained separately.
BRS Pharma Hybrid Balling Method
The popular BRS Pharma with trace elements! Great for heavier demand aquariums and mixes into four solutions for daily addition into the aquarium. Follows the classic "balling method" and eliminates the chloride buildup you get with two-part dosing.
AquaForest Component Bundle
AquaForest Component Bundle is a three-part additive set that maintains all major, minor, and trace elements at the proper ratio they are found in natural seawater.
Tropic Marin Original Balling Set
The original balling method is a three-part system that maintains all major, minor, and trace elements without causing a spike in salinity and the ionic imbalance that occurs with typical two-part dosing.
How much do I need to dose?
A tank's "demand" is how much calcium and alkalinity the corals are consuming each and every day as they grow. A heavy demand means you have a considerable population of stony corals that are healthy and growing and you need to add a considerable amount of additives to keep up. Vice versa for a low or medium demand tank.
To calculate your doses, you will need to test your aquarium's calcium and alkalinity levels daily for at least the first 5 days. When using BRS 2-Part Pharma, we have developed a Reef Calculator to simplify the process. Otherwise, simply follow the manufacturer's recommended minimum dosing amounts. If your daily water tests reveal you are adding too much, reduce the daily dose. If you are not able to maintain ideal levels of calcium and alkalinity, increase your daily dose.
Once you have dialed in your daily dose, simply test the major elements on a weekly basis moving forward to verify things are staying stable.
What is the best frequency and time of day to dose my tank?
Stability is king and the best approach for dosing a one or two-part solution is going to be at least once daily. After determining your daily dose, you can also split up doses throughout the day. For example, if your tank needs 50mL of solution daily, dose 25mL in the morning and 25 mL at night.
You should also never add two-part solutions back to back. In other words, don't dose calcium right after dosing alkalinity, give it at least an hour or so in between adding each solution. An easy approach that works for most tank owners is to dose calcium throughout the day and alkalinity during the evening.
Do I need a dosing pump?
Dosing pumps are not mandatory but sure make your life easy when it comes to using additives. A dosing pump is a peristaltic style pump that accurately delivers the additives for you on a schedule. Most modern pumps are directly programmable but you can also take the more classic approach using a simple timer that turns the pump on/off each day for a set period of time.
Without a dosing pump, you will need to manually measure and dose your additives each and every day. This is tedious and leaves much more room for error.
How often should I test my aquarium parameters?
When first starting out, you need to test for calcium and alkalinity daily. After your daily dosing amounts are dialed, you can adjust to weekly testing. Magnesium can be tested once per week, less often after you feel confident your levels are being maintained. Temperature, pH, and Salinity are very critical as well and should be tested at least once per week if not monitored daily. Phosphate and nitrate are indicators of your tank's nutrient levels and should be tested on a biweekly basis.
Do I need to test for trace elements?
You don't need to test for minor or trace elements until your aquarium is well stocked with stony corals and the corals are growing significantly. As long as your doing a weekly 10% water change, the corals should get what they need.
When you notice your tank starts to consume a considerable amount of two-part solution, it is a good indication it's time to develop a solution for adding trace elements. The BRS Hybrid Balling Method or Tropic Marin Balling Set are great comprehensive dosing solutions as well as the ATI Essentials and AquaForest Component Bundle.
ICP testing is the easiest way to get a snapshot of your minor and trace elements. ICP testing is a mail-in water testing service that tests for over 30 different elements in your aquarium's water. The service is easy and also means you don't need to buy 30 different test kits to get an idea of how your tank is doing in terms of minor and trace elements.
How often should I send off an ICP test?
This really is up to you, most hobbyists won't send an ICP test any more frequently than once per month. It's a good way to verify your home water tests and get a glimpse of your minor and trace elements. ICP testing can also detect a variety of contaminants which is a great tool for identifying problems that you just cannot figure out otherwise.
What do I do if my calcium, alkalinity, and magnesium are not balanced and within the proper range?
If parameters fall out of balance, the easiest course of action is to perform a series of larger water changes to get things back in balance. Once parameters are tested where you want them, start over with your additives in terms of calculating how much to dose daily.
I feel like I am adding WAY too much, am I doing something wrong?
If your tank is not very mature with large corals, this can happen if the additives are precipitating and/or your magnesium levels have dropped. Insufficient magnesium levels in the tank will make it darn near impossible to maintain stable calcium and alkalinity levels. This could result in your constantly increasing your daily dose so don't forget about magnesium.
A precipitation event can also occur if you add too much calcium or alkalinity solution to your tank. This will cloud the water and leave a white residue or calcareous layer on the pumps and other surfaces inside your tank. This precipitation can also occur if you're adding the calcium and alkalinity solutions at the same time or too close together.