Help me get a handle on dosing

[stanleo]

I posted this in my build thread but I would like some help with it if I can.

So I am trying to get a handle on dosing calcium and alkalinity. For 14 days I have dosed Seachem Reef Fusion 2 part. I do half the recommended dose, dosing both parts in the sump return chamber. Part 1, wait a few minutes and then part two. I started dosing both parts after the weekly test two weeks ago showed a drop in calcium and magnesium for the first time after a water change. Last week's test showed a rise in these after dosing daily for a week. Today is water change day so I tested the new saltwater and the tank's water. I think I am on the right track but I would love some feed back from people who understand this better than I do.

January 15 (before dosing both parts)
Alkalinity 9.8 dKH Red Sea (this I had been dosing daily for a while)
Calcium 400 ppm Red Sea
Magnesium 1400 ppm Red Sea

January 22
Alkalinity 9.8 dKH Red Sea
Calcium 420 ppm Red Sea
Magnesium 1440 ppm Red Sea

Today New saltwater using Instant Ocean Reef Crystals.
Alkalinity 10.9 dKH Red Sea
Calcium 450 ppm Red Sea
Magnesium 1520 ppm Red Sea

Today's tank water before water change.
Alkalinity 10.1 dKH Red Sea
Calcium 430 ppm Red Sea
Magnesium 1440 ppm Red Sea

I have kept a chart documenting my weekly tests for the past few months if that helps.

Also, should I dose on water change day and if I do, should I do it before or after I change the water? And how long do I need to wait after the water change before I can test to see what the water change has done to these numbers?

 

[LC8Sumi]

I just wanted to say that I love that chart! Very smart and well executed!

 

[lavoisier]

Are you dosing by hand or with a doser?

I use a doser so I keep a daily schedule of dosing, regardless of water changes. I test alk each day at about the same time of day and other parameters once a week--again about the same time of day. I would imagine that the same approach would work for hand dosing as well.

 

[jsker]

Are you dosing by hand or with a doser?

I use a doser so I keep a daily schedule of dosing, regardless of water changes. I test alk each day at about the same time of day and other parameters once a week--again about the same time of day. I would imagine that the same approach would work for hand dosing as well.

+1

 

[stanleo]

Are you dosing by hand or with a doser?

I use a doser so I keep a daily schedule of dosing, regardless of water changes. I test alk each day at about the same time of day and other parameters once a week--again about the same time of day. I would imagine that the same approach would work for hand dosing as well.

Yes I hand dose, roughly the same time every morning. I test everything the same day and time every week. Wednesday 11 am. Water change is biweekly on tuesday I was testing alk daily but the reading was getting so consistent I stopped and went to weekly.

 

[Js.Aqua.Project]

OK, so I am going to start all the way with the basics and work up to where you are, explaining some of my own reasoning/methodology as well, then on to your specific issue.

Basic concept #1 - Water Parameters need to be stable
All reefers accept this, to be successful long term, we need to keep our environment as stable as possible. As humans we get uncomfortable as our resources diminish (ie-lack of food leads to hunger/hangry), corals get uncomfortable when their resources (Ca, dKH, Mg, trace elements, nutrients [NO3, PO4]) constantly change.

Basic concept #2 - Corals use resources to build skeleton,
Accepted, corals use Ca, dKH, Mg, and Trace Elements to build their skeleton, this therefore lowers the amount of resources available to continue to build their skeleton which means their new skeletons will either stop growing or be thinner/brittle.

Basic concept 3# - Resources must be replenished
Like making a run to the grocery store to restock the fridge, we must replenish the resources that corals have consumed to keep them growing healthily. This can be done multiple ways, through water changes or some form of dosing (supplements or calcium reactor or a combination).

Here is where some of my methodology will differ from some others.

But first, a bad metaphor.

When you need more groceries, do you throw out half of your remaining food before making a run to the store?

By dosing and doing water changes at the same time, this is essentially what you are doing. Paying to add Calcium supplement, then doing a water change which removes some of that supplement before it has the opportunity to be used.

I disagree with the weekly water change as a form of resource maintenance unless there is a problem than can only be solved with a water change.

I want clarify, I am not anti-water change. It just doesn't compute for me to do a water change AND dose at the same time.

In a perfect world, every scoop batch of salt is equal parts Ca, dKH, Mg and trace elements are in proper ratios. In reality, this is not the case, especially in lab mixed salts. So every time you are doing a water change, unless you are mixing a full bag/box/bucket, you aren't putting everything back in the tank in the proper balance.

For this reason, I don't do water changes, I routinely test (Trident and Red Sea) and dose as needed. This includes dosing my trace elements in ratio to my Calcium (I use Red Sea's Trace Colors).

::gets off soap box::

Now to address your specific issue:

Reef Fusion has led to some confusion with other reefers that I have met that started out with it. Primarily it was because they read the instructions as "add this much every day and everything will stay in balance". The information you really need is a little further down on the label.

Reef Fusion 1 will add 4ppm of Calcium for every 1ml dosed into 25L (6.5 gal)
Reef Fusion 2 will add .176 meq (.49 dKH) for every 1ml dosed into 25L (6.5 gal)

So instead of doing a "half dose daily", you should be adding whatever amount is required to keep your environment stable. Here, a lot of reefers choose to match their salt parameters that way if you need to do a water change, you are in theory adding back salt at the same parameters you are keeping your reef at.

The theory behind their methodology is supported by the theory that corals consume Calcium and Alkalinity at a fixed ratio. Therefore, if testing Ca and dose them at 1:1 to maintain Ca level, the Alkalinity will stay in balance with my Ca.

 

[lavoisier]

Yes I hand dose, roughly the same time every morning. I test everything the same day and time every week. Wednesday 11 am. Water change is biweekly on tuesday I was testing alk daily but the reading was getting so consistent I stopped and went to weekly.

I get not wanting to test alk everyday. Daily testing is another way to get a potential "early" warning. If your alk rises (uptake in tank decreases) it may let you know your corals are stressed by something. Maybe cut back to 2 or 3 times a week?

 

[stanleo]

Now to address your specific issue:

Reef Fusion has led to some confusion with other reefers that I have met that started out with it. Primarily it was because they read the instructions as "add this much every day and everything will stay in balance". The information you really need is a little further down on the label.

Reef Fusion 1 will add 4ppm of Calcium for every 1ml dosed into 25L (6.5 gal)
Reef Fusion 2 will add .176 meq (.49 dKH) for every 1ml dosed into 25L (6.5 gal)

So instead of doing a "half dose daily", you should be adding whatever amount is required to keep your environment stable. Here, a lot of reefers choose to match their salt parameters that way if you need to do a water change, you are in theory adding back salt at the same parameters you are keeping your reef at.

The theory behind their methodology is supported by the theory that corals consume Calcium and Alkalinity at a fixed ratio. Therefore, if testing Ca and dose them at 1:1 to maintain Ca level, the Alkalinity will stay in balance with my Ca.

Ok full disclosure, I have always stunk at math but let me see if I have this right.

I have been doing two caps of part 1 (10mL according to the bottle) a day which is 40 ppm, right? I have been doing 1 cap of part 2 (10mL according to the bottle) a day which is 5 dKH. So considering I have a 120 gallon tank with about 20 gallons in the sump and the recommended dose is 20mL of each, then I am adding 20 ppm of calcium and 2.5 dKH of alkalinity. I honestly have no idea if I just made any sense.

So I have more questions. How do I know how much to dose? I thought I could do this for a month, collect the data and adjust my dosing. I am not comfortable testing for all the trace elements like iodine and strontium and dosing those which is why I do 20 gallon water changes every two weeks. So should I test alk, cal, mag every day for a week without dosing and figure out how much is being used and then dose just what is being used?

Another question, how do I KNOW how much water is actually in my system? Does KNOWING that actually matter? Can I just go by the 140 gallons that is the size of the tank and sump?

And, how do I know when I am stable cause honestly, I thought I was? My numbers always stay within a certain range, not too high, not too low. (the highs in the beginning of that chart are due to testing errors.) I thought that was stable. Do they HAVE to be the same number at every test to be considered stable? Is that even possible?

 

[Randy Holmes-Farley]

The theory behind their methodology is supported by the theory that corals consume Calcium and Alkalinity at a fixed ratio. Therefore, if testing Ca and dose them at 1:1 to maintain Ca level, the Alkalinity will stay in balance with my Ca.

The theory is an excellent one that is the basis for most dosing methods. Sadly, and very surprisingly, Seachem gets the ratio wrong so that it is not properly designed for 1:1 dosing. it is too much calcium for the amount of alkalinity for 1:1 dosing.

 

[Js.Aqua.Project]

Ok full disclosure, I have always stunk at math but let me see if I have this right.

I have been doing two caps of part 1 (10mL according to the bottle) a day which is 40 ppm, right? I have been doing 1 cap of part 2 (10mL according to the bottle) a day which is 5 dKH. So considering I have a 120 gallon tank with about 20 gallons in the sump and the recommended dose is 20mL of each, then I am adding 20 ppm of calcium and 2.5 dKH of alkalinity. I honestly have no idea if I just made any sense.

So I have more questions. How do I know how much to dose? I thought I could do this for a month, collect the data and adjust my dosing. I am not comfortable testing for all the trace elements like iodine and strontium and dosing those which is why I do 20 gallon water changes every two weeks. So should I test alk, cal, mag every day for a week without dosing and figure out how much is being used and then dose just what is being used?

Another question, how do I KNOW how much water is actually in my system? Does KNOWING that actually matter? Can I just go by the 140 gallons that is the size of the tank and sump?

And, how do I know when I am stable cause honestly, I thought I was? My numbers always stay within a certain range, not too high, not too low. (the highs in the beginning of that chart are due to testing errors.) I thought that was stable. Do they HAVE to be the same number at every test to be considered stable? Is that even possible?

For calculating the amount to dose you need 4 numbers; the current level, the desired level, and the water volume of your tank (will talk about figuring this out in a second), and the dosing amount per gallon (as stated in my previous post 1ml per 6.5 gals = 4ppm Ca).

So the first two numbers are simple to obtain; test your aquarium and get the current Ca level and know the Ca level of your salt (I see you are using Reef Crystals which I believe sits around 450).

So if you are trying to go from 430 (from your first post) to 450 (salt level) you need to dose 5ml/6.5gal to reach that level. So for your tank 20/6.5 = 18.5ml.

So you will notice I didn't worry about your sump or rock yet, hang in there.

Do a test right before you dose (correct dose if it is different than the 430 from before) and 30 minutes after you dose (to give the supplement enough time to fully mix in).

Now you can calculate the actual water volume of your system.

Follow the logic here:

If 1ml will raise 6.5 gallons by 4ppm, you now will have 18.5 ml raised x gallons by y ppm. Here Y equals the ppm increase from the second test. Solve for x and you have your actual system volume.

1:6.5 = 4 becomes 18.5:x = y

Knowing your actual water volume makes your dosing more accurate.

To answer your question on stability, in a perfect world stability means the numbers are exactly the same every single time and there are people that achieve that through constant testing at dose adjustments. For me, I am fortunate enough to have an Apex and a Trident with automated dosing adjustments to assist me in keeping my tank stable - that doesn't want I don't routinely double check myself with manual testing.

Realistically, I consider the following to be "stable" but others may disagree. Remember these are in reference to your target parameters.

Ca +/- 5ppm
dKH +/- .2
Mg +/- 10ppm

Personally I am not a fan of Reef Crystals because the parameters are not readily accessible and presented as a range. I use Red Sea Coral Pro because they say what the parameters should be with a simple number. I am not saying you have to use that to be successful, but try checking out their dosing system as I find it to be straight forward (even the trace dosing is simple, dose each of the 4 parts at a 1:10 ratio to how much calcium you dose).

 

[stanleo]

For calculating the amount to dose you need 4 numbers; the current level, the desired level, and the water volume of your tank (will talk about figuring this out in a second), and the dosing amount per gallon (as stated in my previous post 1ml per 6.5 gals = 4ppm Ca).

So the first two numbers are simple to obtain; test your aquarium and get the current Ca level and know the Ca level of your salt (I see you are using Reef Crystals which I believe sits around 450).

So if you are trying to go from 430 (from your first post) to 450 (salt level) you need to dose 5ml/6.5gal to reach that level. So for your tank 20/6.5 = 18.5ml.

So you will notice I didn't worry about your sump or rock yet, hang in there.

Do a test right before you dose (correct dose if it is different than the 430 from before) and 30 minutes after you dose (to give the supplement enough time to fully mix in).

Now you can calculate the actual water volume of your system.

Follow the logic here:

If 1ml will raise 6.5 gallons by 4ppm, you now will have 18.5 ml raised x gallons by y ppm. Here Y equals the ppm increase from the second test. Solve for x and you have your actual system volume.

1:6.5 = 4 becomes 18.5:x = y

Knowing your actual water volume makes your dosing more accurate.

I did my weekly test and these are the results

Temp 78F
Salinity 35 ppt
pH 8.1 API
Alkalinity 10.1 dKH Red Sea
Calcium 420 ppm Red Sea
Magnesium 1440 ppm Red Sea
Phosphate .1 ppm Salifert
Nitrate 2 ppm Salifert

Besides the .2 increase in alk they are the same as last week's numbers.

As stated I am terrible at math. I took algebra 25 years ago and I almost failed. But let me give this a shot.

My cal is 420 and I want to dose to 450 because that is what my salt mix is. 120 gallons divided by 6.5 is 18.5 roughly. So I need to increase cal 30 ppm. 30 divided by 4 is 7.5. So I would need 7.5 mL of part 1 per 6.5 gallons. That just cannot be right. So 7.5 times 18.5 is 138.75mL. That has to be way to much to dose at one time.

 

[stanleo]

So if you are trying to go from 430 (from your first post) to 450 (salt level) you need to dose 5ml/6.5gal to reach that level. So for your tank 20/6.5 = 18.5ml.

This is where you lost me. I get how you come up with 5mL per 6.5 gallons of water. But even that is 92.5mL and that is still too much to dose at one time. What am I missing? How do you come up with 20/6.5 = 18.5 mL

 

[Js.Aqua.Project]

When dosing, we think more of "I can't raise it by that at one time" not "that is too much to dose at one time".

For example, Calcium should generally not be raised by more than 20ppm in one day.

So here was my logic that got me to 5ml/6.5gal.

1ml/6.5gal will raise Ca by 4ppm.

We wanted to increase Ca by 20.

So 20/4=5 times dose, 5 x 1 = 5 so 5ml will raise 6.5gal by 20ppm.

120/6.5 = 18.5 so 5 x 18.5 = 92.5 so 92.5 ml will raise 120gal by 20ppm.

Looking back there may have been a typo in my original message (was on my phone).

 

[Js.Aqua.Project]

In response to one of your earlier questions; it is possible to test today, then again in four days then look at your consumption. Then you would do a one time dose to get back to your original number, afterwards divide that dose by 4 and you will have your daily uptake rate.

You will still need to test regularly to make adjustments to that dose if your numbers are rising or falling outside your target parameter window.

 

[stanleo]

So 20/4=5 times dose, 5 x 1 = 5 so 5ml will raise 6.5gal by 20ppm.

120/6.5 = 18.5 so 5 x 18.5 = 92.5 so 92.5 ml will raise 120gal by 20ppm.

I figured that was a typo. So my math was right and it's safe to dose that much at one time? Increase by 20, not 30 anyway. Ok I will try that tomorrow and test before and after. Thank you.