My recent dosing mess-up

[LouisianaReefer]

Ok. This situation/problem will betray my dire need for more experience. Here goes...

I have a 75 gallon DT with 30 gallon sump. It is a mixed reef with mostly softies, LPS, and monticaps as my only SPS corals.

I have been testing my parameters using Red Sea's Foundations kit. Levels needed to be increased a bit in Alk, Mg, and Ca. The booklet that comes with the kit says at the bottom of p. 6: "In order to prevent the effects of unbalanced levels of the foundation elements the supplements should be added in the following order allowing 10 minutes between each: 1st - Magnesium, 2nd - Alkalinity, 3rd - Calcium." I dosed Mg and waited at least an hour before dosing Alk. I believe it was the next morning that I dosed the Ca. All were dosed into the sump according to my directions for each supplement.

The next day, many of my corals were very stressed. Perhaps I do not have enough flow in my sump. I really do not know what went wrong. I think that advice from Seachem does not work well for some folks. Still, maybe I did something wrong. I appreciate any input.

I ended up doing a 10 gallon water change which helped greatly. At least one softie is still struggling. I do not plan to dose more than one supplement at a time again. My current levels now are:
Mg 1200
KH 3.6 meq/L 10.1 dKH
Ca 395

[bertoni]

How much of each did you add?

[LouisianaReefer]

I under-estimated my water volume I believe. I assumed about 90 gallons as total volume and added according to the directions on the containers for each product. I use Seachem's Ca & Mg. I used Kent Supperbuffer to bring up the KH. I am not home; I will have to look later to see the exact amounts/teaspoons per gallon. I have dosed each of these 3 before with no problems. This was my first time dosing all 3 so close together in time together.

For some of the directions, it may have given the range of 1 teaspoon for every 30-40 gallons. In such cases, I only used 2 teaspoons.

[dkeller_nc]

It's not impossible that the alkalinity in your system may have swung quite widely based on dosing the Alk supplement and then waiting 8 hours or more to dose the Ca supplement. The magnesium supplement won't make any difference unless the amount dosed was incorrectly calculated.

Keep in mind that Kent's super buffer will increase your alkalinity in addition to the boost from the Seachem Alk supplement. Moreover, unless the Seachem Alk supplement amount is reduced in proportion to the amount of Super Buffer used, you're adding an unbalanced amount of Calcium and Alkalinity.

Since you have an alkalinity test kit, I'd test over a few days to see how much your tank is consuming, and calculate how much of the alkalinity supplement is required to maintain that, rather than going by the bottle directions.

[LouisianaReefer]

It's not impossible that the alkalinity in your system may have swung quite widely based on dosing the Alk supplement and then waiting 8 hours or more to dose the Ca supplement. The magnesium supplement won't make any difference unless the amount dosed was incorrectly calculated.

Keep in mind that Kent's super buffer will increase your alkalinity in addition to the boost from the Seachem Alk supplement. Moreover, unless the Seachem Alk supplement amount is reduced in proportion to the amount of Super Buffer used, you're adding an unbalanced amount of Calcium and Alkalinity.

Since you have an alkalinity test kit, I'd test over a few days to see how much your tank is consuming, and calculate how much of the alkalinity supplement is required to maintain that, rather than going by the bottle directions.

[LouisianaReefer]

I only use the Kent Supper Buffer. I do not use or have the Seachem Alk product because it is too difficult to dissolve. I did not dose for Alk and Ca at the same time because I was concerned that doing so would have been too stressful for the tank. Is the opposite true? I guess I should have dosed closer in time? Perhaps that is why it is called 2 part dosing? Anyone know some basic literature (articles or prior posts) that can help a newbie like me? It would be good to understand the basic chemistry better.

Thanks for the great advice! Perhaps I can use the test kit on the day following my dosing to indicate approximately how much each 1/2 teasoon increases the Alk. That would take out some guesswork. It would take some time; however I could also determine that for the Mg and Ca as well.

[dkeller_nc]

The issue with dosing one component of the Ca & Alk supplements and not the other for many hours is the possibility of precipitating calcium carbonate. Note that I say possibility; whether or not this will actually happen depends on what your absolute Ca and Alk numbers are, the temperature of the tank, and several other variables.

However, you usually can't dose the Ca and Alk simultaneously because the liquids don't have enough time to mix with the tank's water volume, and of they come in contact with each other, they will definitely precipitate.

But you don't need to wait long. In my case, I add one solution and then the other within a couple of minutes of each other. Some play it safe by separating their additions by 30 minutes or so. Either regime works.