Why would I need to add calcium?

[rdefino]

I have a 75FOWLR. Why would I need to add calcium?

 

[steve-s]

For a 75 gal FOWLR, you most likely will never need it. Depends on the coralline growth you get if any but primarily scleractinians are going to be your largest/main consumers. Without them, water changes should keep up just fine depending on the salt mix.

Cheers
Steve

 

[captivereefs]

Just for corraline growth. Just do regular water changes as mentioned above and you will be fine with out it.

 

[Phyl]

My tank drops approximately 60 units a day (on a salifert test) with 120 IOWLR right now (tail end of a cycle with no fish). I'm interested in promoting the coraline growth so have been watching the numbers and dosing with calcium (and alk to keep them together) as it gets used up. I'm very surprised at how much I go through a day.

 

[steve-s]

Cycling is havoc on the chemistry for the most part so I would suggest you look more to the depletion rate afterwards. What goes on during the cycle will lead you awry. Alkalinity will yo-yo dramaticly as will the pH so if you are constantly adding buffer it will force down the Ca levels chemically depending on Mg and not as a result of animals depositing CaCO3. A 60 ppm daily draw without scleractinians or heavy coralline growth doesn't add up.

Are you cycling with base rock or LR?

Cheers
Steve

 

[Phyl]

There's 85# of base in the tank, 60# of LR (30GR & 30KR from LR.com) There are a bunch of clams that came aboard the rock. I'm at the tail end of my cycle. Ammo has been 0 for weeks now. My nitrites are just about to zero (also for weeks now) and my trates are around 5 or 10 (climbed up a week or so ago but have been holding fairly steady). The PH and Alk don't change dramatically. My PH is a little on the low side (?) at around 8.0 but it has been there from jump. Always the same. My alk slowly drops as my calcium plummets. I have one golfball sized coral colony on one of my rocks (Cladocora) and two small colonies on another rock. There's another polyp or two near my big clam. Anything in there sound like it should be riffling through ca? I *THINK* I'm seeing more purple on my rocks and am definitely seeing spots (lol) on one of my base rocks. What would qualify as heavy coraline growth?

 

[steve-s]

Anything in there sound like it should be riffling through ca?

Not really.

What would qualify as heavy coraline growth?

Cleaning the glass every few days of coralline "spots" and coralline on the rock areas would have visible growth areas. One patch is definately a good sign but there's not enough "overall" growth to consume that much Ca. Nor are there enough scleratinians or mollusks/univalves.

Could still be there is some pull from the animals but I think you'll find as the tank moves out of the cycle stage and gains some stability, the chem will not do this so much.

Curious, have you been doing water changes during the cycle and if so, what saltmix?

Cheers
Steve

 

[Phyl]

The salt mix that I used when I setup the tank was IO with tap (10/29; phospates tested 0 at the 2w mark). I did a 20% water change on 11/17 with LFS RO/DI water. That was the day that the LR went in to the tank. The Saturday after that was the first time I tested my Ca at 420 and it has been rolling downhill ever since! Don't know what salt the LFS uses in their premixed.

Glad to hear that the tank will stablize. Do you think I should just stop watching these numbers for now or should I keep up with them to prevent any losses to the inverts and LR?

 

[RocketSeason]

can someone lead me to a great place to buy a great calcium/alkalinity testing kit? My LFS doesn't carry any.

thanks!
-Matt

 

[cmor1701d]

Do a google search on Salifert or Seachem. Lots of online stores carry them.

 

[steve-s]

Do you think I should just stop watching these numbers for now or should I keep up with them to prevent any losses to the inverts and LR?

If your doing regular water changes I don't think you'll need the alk/Ca testing but I would keep up the others.

If I understand you correctly, you buy your SW premixed from the LFS? If so, that might be your Ca drain, not the tank. Most likely the LFS also uses IO salts which is quite low in Ca. Water changes are what's lowering the Ca moreso that the tank critters/rock.

That is unless you only change the water weekly and test daily, just a stab in the dark.

Cheers
Steve

 

[Phyl]

I did my first (and only) water change on 17th. The 19th was the first day of testing. Tested at 420ppm. Tested Saturday. Down to 400, Sunday 360(?). Dosed with 3tsp of Kent Ca (am), brought it back up to 380 evening. The next day it was back down to 360 so I dosed 6 tsp. That brought be up to 400, but by the next day it was back down again to 360. Dosed 9 tsp over the next day. That brought me back up to 420. Added another 6 and am now up to 450. I am testing the Ca and Alk daily since it was changing so fast.

The original water was also IO so no better/worse than what the LFS is doing for me. I need to find a source of better salt.

Since there are no fish in there yet (filter media's been in the system for 2w now so we're ready to move it to a QT tank) and I'm still trying to finish my cycle (ammo 0, trites 0, trates 20) I'm not doing regular water changes, per se. Will probably do one this weekend though.

 

[steve-s]

Truely I think it's a combination of things but not one stand alone issue to be concerned about. I would still think the cycle and possible the saltmix are your main contributors. Some will also be from the rock, abiotic precip and the inverts you mention.

From the 19th your total consumption is about 100 ppm +/- (?) based on your above post so really in 14 days, that's only about 7 ppm total change each day spread out.

Large swings are more likely to be chemical in nature rather than animal use which for the most part, is steady daily decreases.

Cheers
Steve