understanding dosing, how do you know what you need?

[Fresh_Water Reefer]

So, I've never had a salt water tank, let alone a reef tank. I understand that with corals there is a must to dose certain supplements into the water for health and growth of said corals. Like the title states, how do you know what you need to dose, and in what increments? Is this something thats understood from what corals you purchase, or is it more of a general, across the board approach? As I'm planning my tank build, I really like the thought of auto dosing, mainly because I'd like to be as hands off as possible aside from water changes. Can someone get me up to speed on understanding dosing and how one goes about knowing what they need to dose?

 

[New&no clue]

It will depend on your corals (soft, LPS, SPS) all of these will be different. Soft will require the least and usually a water change is enough to replenish the items needed. SPS will be the most and can require daily dosing. While I think automation is great, I also think it's good for you the learn your tank.

The best way to start is to start testing your parameters each week and track your results (Calcium, Magnesium, Alkalinity, Nitrates, Phosphates). Make sure you get good, reliable test kits. You can go simple and write it down in a notebook, or get an APP on your phone to track it. See what is being depleted and by how much each week. Then you can see what you need to dose. It's also important to get your tanks baseline and stick to that. Don't chase numbers that others have, find what your tank is thriving at and maintain it.

My tank is 8 months old. I test my water every week. So far I only dose Alk. I have a mix of soft, LPS, and a couple SPS.

 

[piranhaman00]

You need a test kit for anything you are dosing. Measure your aquariums use, and dose the difference.

 

[lapin]

You will get a lot of ideas about dosing.
As I see it you dose to replace what the tank is using up.
How you do this varies
Water changes can replace a lot of whats used up. When the amount of water being replaced becomes an inconvience then people dose.
Some go full on automated pumps, tanks ect....
Some just add kalk and call it a day,
Others run a calcium reactor.
To know when to dose and what you must first measure elements in your tank water. Calcium, Alkalinity and Magnesium are the big 3.
There are tons of other trace elements. Whether dosing them is needed or not is debatable. Much depends on if you do water changes or not and how much and how often.

Disclaimer: I do 10% water changes every week and run a calcium reactor. I do not dose.

 

[Fresh_Water Reefer]

It will depend on your corals (soft, LPS, SPS) all of these will be different. Soft will require the least and usually a water change is enough to replenish the items needed. SPS will be the most and can require daily dosing. While I think automation is great, I also think it's good for you the learn your tank.

The best way to start is to start testing your parameters each week and track your results (Calcium, Magnesium, Alkalinity, Nitrates, Phosphates). Make sure you get good, reliable test kits. You can go simple and write it down in a notebook, or get an APP on your phone to track it. See what is being depleted and by how much each week. Then you can see what you need to dose. It's also important to get your tanks baseline and stick to that. Don't chase numbers that others have, find what your tank is thriving at and maintain it.

My tank is 8 months old. I test my water every week. So far I only dose Alk. I have a mix of soft, LPS, and a couple SPS.

Beautiful tank! How do you get a base line to start? I feel dumb for asking, but are those elements found in water at the start, or do you do an initial dose? How do you know how much of those elements you'll need? You can easily over dose right?

 

[Fresh_Water Reefer]

You will get a lot of ideas about dosing.
As I see it you dose to replace what the tank is using up.
How you do this varies
Water changes can replace a lot of whats used up. When the amount of water being replaced becomes an inconvience then people dose.
Some go full on automated pumps, tanks ect....
Some just add kalk and call it a day,
Others run a calcium reactor.
To know when to dose and what you must first measure elements in your tank water. Calcium, Alkalinity and Magnesium are the big 3.
There are tons of other trace elements. Wether dosing them is needed or not is debateable. Much depends on if you do water changes or not and how much and how often.

Disclaimer: I do 10% water changes every week and run a calcium reactor. I do not dose.

Sorry, you answered some of my questions while I was typing my other response lol

 

[lapin]

Beautiful tank! How do you get a base line to start? I feel dumb for asking, but are those elements found in water at the start, or do you do an initial dose? How do you know how much of those elements you'll need? You can easily over dose right?

In a reef tank we know what works and have base line numbers. We dose based on them. Humans on the others hand, dose themselves, without ever testing what the body really needs. I find that funny.

Optimal Parameters for a Coral Reef Aquarium: By Randy Holmes-Farley

[note: edited on 5/29/2022 to update the nitrate and phosphate sections with higher recommended levels.] One of the main roles of an aquarist with a coral reef aquarium is to ensure that the conditions are right for their tank inhabitants. There are many different attributes of the aquarium...

www.reef2reef.com

 

[New&no clue]

Beautiful tank! How do you get a base line to start? I feel dumb for asking, but are those elements found in water at the start, or do you do an initial dose? How do you know how much of those elements you'll need? You can easily over dose right?

Your salt will have all the parameters in it. If you look on the bag or bucket it should state what the parameters are when mixed

It is easiest to make that your starting point. Now you want to maintain that going forward. Every time you do a water change you are adding these elements back in with the fresh water, and sometimes that is enough. The more corals you add the more elements will get used up. At the start a weekly water change should be all you need.

 

[Miller535]

When your tank is new, and you only have small corals, if you do regular water changes, you will likely not need to dose. The new saltwater you are using for water changes will have everything they need. As they grow, the elements they are typically called "The big 3" was start to deplete. These are Calcium, magnesium, and alkalinity. Mostly calcium and alkalinity. Most beginners either dose these by adding kalkwasser to their top off water, or dosing them. If dosing them it is important to remember that Alk and Cal are consumed by corals at the same rate. Many newbies do not realize this, and only dose one, or dose them in unequal ammounts and end up with water chemistry issues. But like I said, you should not have to dose anything for a while if you do regular water changes. This generally is 10% per week, or 25% biweekly, imo.

 

[Fresh_Water Reefer]

Awwwww OK ok, its making sense now, thank you all! So, just to recap, the salt being used is what sets the baseline for the tank, those numbers for each element is what we are shooting to maintain consistently. Regular water changes replenish those without the need for extra dosing. Once corals have been added and they begin to grow the need to have additional dosing will arise though, hence where an auto doser or a reactor would come into play.

Now, I have to ask, how does a reactor work in keeping certain elements at certain levels, and is there a risk of a reactor producing too much a certain element, such as calcium?

 

[Miller535]

Awwwww OK ok, its making sense now, thank you all! So, just to recap, the salt being used is what sets the baseline for the tank, those numbers for each element is what we are shooting to maintain consistently. Regular water changes replenish those without the need for extra dosing. Once corals have been added and they begin to grow the need to have additional dosing will arise though, hence where an auto doser or a reactor would come into play.

Now, I have to ask, how does a reactor work in keeping certain elements at certain levels, and is there a risk of a reactor producing too much a certain element, such as calcium?

Yes, you got it. The main reactor I know of that people use is a calcium reactor. I have never personally used one. Even though it is called a calcium reactor, it is actually dosing both alk and cal by dissolving media. But they are pretty expensive to buy all the equipment and set up. And yes, they can overdose so they require some dialing in and monitoring and testing. I personally find dosing 2 part (alk and cal with dosers much easier). You can even dose 2 part by hand if you are worried about over dosing, or do not have the money yet for dosers.

 

[lapin]

To add to the above
Kalk in your ATO can be an issue if the ATO malfunctions dumps all the water into the tank
This can also happen with dosers.

 

[New&no clue]

One more thing with Kalk is it depends on your ATO setup if you can use it. You need to be pulling water from about an inch off the base of the ATO. It doesn't work for either of my tanks, one is gravity fed so the water comes from the bottom. The other my pump pulls from the bottom not the side.

 

[Fresh_Water Reefer]

One more thing with Kalk is it depends on your ATO setup if you can use it. You need to be pulling water from about an inch off the base of the ATO. It doesn't work for either of my tanks, one is gravity fed so the water comes from the bottom. The other my pump pulls from the bottom not the side.

so do you have to use your ATO as a way of maintaining water perimeters, or could this be handled with just manually dosing Kalk?

 

[Miller535]

so do you have to use your ATO as a way of maintaining water perimeters, or could this be handled with just manually dosing Kalk?

You do not need to use your ato to maintain water parameters. But you do not manually dose kalk. When you mix kalk, at the bottom of the bucket there are almost like curdled milk clumps. Because of this you do not use the bottom inch or so. Some people will use a kalk dripper though. And from what I understand this works well for manually adding. You can also use a Kalk reactor if you are interested in using kalk.

 

[Fresh_Water Reefer]

ok, so kalk isn't something that you have to have?

 

[Miller535]

ok, so kalk isn't something that you have to have?

No, it is one option of dosing alkalinity and calcium.

 

[mike550]

@Fresh_Water Reefer you've gotten a ton of great advice here. But like @New&no clue I'm new to the hobby and my tank is about ten months old -- although not nearly as impressive as New@no clue's! But here's what I've learned along the way.

Start with your salt. It will define a "baseline" for the key parameters of Alk, Ca, and Mg. So if you can find a salt close to the parameters you like start with that. Fair warning, many people like certain salts because they can control the three parameters through dosing, reactors, etc. Personally starting out like that seemed to be too complicated. I wanted to start simple and add complexity only as required. BRS has a lot of helpful videos on salt.

I've always measured my tank parameters every three days (salinity, phosphate, alkalinity, calcium, magnesium, and nitrate) but didn't start dosing until a few months ago. Then I was only dosing for alk -- and doing it by hand. As my tank has evolved, I'm now dosing alk, Ca, and Mg with a doser. But I completely agree that you need to get a "feel" for your tank and not manage to the numbers.

Take your time as you build your tank and equipment. The only thing that seems to move quickly in this hobby are disasters.

 

[LC8Sumi]

The main idea is that there are baseline numbers, the most obvious being the sea for example at great barrier reef.

There is also a chemical balance, or ratio in other words, about how much each of the elements corals are pulling out of the water column to form their skeleton (Calcium Carbonate). Like for every x part of calcium, they need y part of carbonate. The ratio between x and y is fixed by nature/chemistry and is known.

The aim is to keep the parameters in the water close to a given set point (sea for example), and knowing the ratio how corals pull the elements out of the water, you know how much to "put back" into the water, even if you only test for one of the big two elements (Calcium or Carbonate).

Some additives take this a step further, and mix in some trace elements (Zink, Molybdenum, Iron, Iodine, etc.. etc..) in the required ratio (as they've observed how much corals take up) into the additive liquids, or offer them as seperate cocktails, and tell you how much to dose based on Calcium dosage for example. (The ratio between Calcium and minor elements are also fixed, and known)

There are thus now additives, where you use 2 or 3 liquids or even only one (cocktails), and you are able to measure only one of the main elements (Carbonate for example, as that's one of the fastest/easiest/most accurate to measure & also this is the one that is consumed the fastest out of the three major)), and set the dosing of both or all 3 liquids based on that to achieve natural levels of all of the elements in the water of the tank.

It is like heating up a house by burning wood.. Let's say you want to keep a stable 73F temperature and that the outside temperature is always 60F (just for easy understanding).
You can measure how many logs you have to burn a day to keep the temperature at this value. Then you start opening windows (put in corals), so some of the temperature is pulled out of the house, hence you have to put more logs onto your fireplace to achieve the same 73F. You could observe how much additional logs are needed for this on a daily basis, and the next day you would exactly know the number of logs needed, even without looking at the tempreture sensor.
Then perhaps once every week, you look at the sensor, just to be on the safe side, because the outside temperature might have changed a bit, or a window seal has degraded over the week, and you then adjust the number of daily logs, to get back to the target temperature.

 

[New&no clue]

I really like Red Sea products they have some good videos on dosing, and the one below is how Cal, Mag, and Alk are used by your corals. I found it a good intro to dosing.