dosing

[chizzle]

Went to the LFS & purchased some new GSP (will post some pics when they open ). They LFS guy was absolutely amped on selling us some iodine. He insisted that polyps & mushrooms required it to thrive properly. We didn't buy it because everything is doing fine in our tank, but I just wanted to make sure everything would get what it needed from water changes.

Also, on a side note, we got the polyps for $14, and normally we don't spend any less than $50 when we go. Today we only got the polyps. I'm assuming that is why he was so amped on selling us something else, but I just wanted to make sure that we didn't need it.

And one more question...we buy our RO/DI water from them & we do have to buffer it. The buffer we have been buying (bear with me here) is Reef something-or-another with a purple label & says raises pH to 8.3. We tried to sell us something else, same brand, but with a pink label that said raises carbonate alkalinity. Our alkalinity has always tested between 10-11, and our calcium has always tested between 480 & 520. LFS guy said we should switch because of our alkalinity & calcium, but that isn't the issue, its the pH.

I'm sure he was just trying to get a sale, but I just wanted to run it by everyone for another opinion. Thanks & sorry for the long (slightly confusing) post

 

[Ziggy953]

You were right on NOT buying the iodine. If you do regular water changes you will be just fine. I have mushrooms growing out my ears and my GSP is doing great. I do 20-25% water change every other week.

How long has your tank been set up for? What are your other water parameters?

 

[chizzle]

The 75 has been up since January 1 (easy date to remember ) Everything is testing out at 0 (amm, trates, trites) pH 8.1 but stable, temp 75, calcium 480 today, alkalinity 10, phosp 0. Did I miss any?

When I mentioned what our calcium was at, he asked what we were dosing with and I said we just do PWC on a regular basis, he looked kind of shocked & said, "Well you are lucky for right now." Just looking for more of a sale I assume.

Thanks for the quick response, glad to know I was right

 

[melosu58]

Just looking for more of a sale I assume.

That what he was doing. I just do PWC`s and have them growing all over the place. No dosing necessary for iodine if you are doing PWC`s.

 

[MT79]

Everyones so cynical! lol j/k The only time you'll really see alk/ca demand is w/ stoney corals, and maybe a slight increase as the amount of coralline, etc increases w/ time as the tank matures. FWIW CA 480-500 is a bit on the high side.

And one more question...we buy our RO/DI water from them & we do have to buffer it.

After you had salt mix? If so, how long do you mix the new SW and how?

 

[Devilishturtles]

What does your pH test at before the buffer?

 

[chizzle]

Before the buffer its at 7.0, after salt mix its 7.6-7.8, then with the buffer its stable at 8.1. As for the calcium, is there a way to lower it? That's where it is with just doing PWCs. Is there a downfall/side effect for having high calcium?

 

[lando]

having a high CA level may be contributing to your Ph issues. Higher CA means lower ALK. Alkalinity is a measure of the water's resistance to changes in Ph. A higher ALK reading suggests more resistance of Ph swings ( and vice versa). By lowering CA to around 400 should drive ALK up, therefore, increasing your water's resistance to chage in Ph. Also, test Ph at different times of the day. In the morning after the tank has been dark all night and in the eveing once the lights hve been on a while. If you at all concerned, get a second test kit to verify results. Don't bother having the LFS test Ph for you if you are, the transit time of the sample will have a great effect on the Ph.

Good call not dosing iodine. It is one of the more specific elements to be dosing and it is very easy to over-dose your tank. If you do not test for, do not add it.

 

[MT79]

after salt mix its 7.6-7.8,

What brand salt mix? How do you mix it -trash can w/ a power head etc.? Is the container open to air/gas exchange? What is the Alk of your fresh SW? Usually new SW will not need buffering to get PH up when mixed properly. Only if the ALK level is low should you add buffers. They only increase PH temporarily, but drive up Alk until it's used or causes issues. CO2 amounts generally will have a much greater effect on PH.

Is there a downfall/side effect for having high calcium?

Only in that having your Ca somewhere in the middle, 380-440, allows for error in the test kit as well as the user, and also will allow for any errors in dosing. If CA goes to high (~520+), it will not only negatively impact coral, but also possibly precipitate out of solution leading to larger issues.

By lowering CA to around 400 should drive ALK up,

Not necessarily. Alk will need to be boosted to increase, regardless of CA level. They are independent of each other in that sense. They are really only balanced in the rate they are both generally consumed by coral, etc. It's possible to run both high CA and Alk if desired.

 

[rayjay]

One of many articles that can help.
UNDERSTANDING THE RELATIONSHIP BETWEEN CALCIUM, ALKALINITY MAGNESIUM AND pH

As a side note:
I don't have any stoney corals in my ten tanks and I have to continually dose limewater (about 22 litres nightly) or two part additive for calcium and alk.
If you have corals that grow skeletons, they use the calcium and magnesium, as does my halimeda algae and coralline.

 

[chizzle]

I'll make sure I test all the water in all the different stages. Thanks for all the help, it definitely makes sense.