Why doesn’t my calcium drop?

[galantra]

So currently right now I have a mix reef with probably more sps currently in my tank. Towards the start I had to add both calcium and alkalinity to get to the levels I needed before adding any corals into the tank. Since adding only thing that’s been dropping is Alk. So currently my
Calcium is at 484ppm
alkalinity 156ppm and been dosing to keep numbers around 160ppm which actually been staying around this number. Calcium I haven’t dose for about 4 weeks and before for 4 weeks I only been dosing at 1ml.

total water volume of tank is 100-110g and been doing 10 percent weekly water changes with the use of reef crystals.
Yes I know my Ca is high, which was from over dosing before hence why I stopped dosing Ca.

My issue is can this be normal only needing Alkalinity for this long?
Test kits are redsea and Hanna checker and they pretty much match

My issue is can this be normal only needing Alkalinity for this long?

my corals are doing good with great growth with certain frags

 

[dwest]

It’s pretty common that people need to add an imbalanced amount of alkalinity and calcium. My tank requirements are more balanced right now, but Ive read many threads over the years about situations like yours. I wouldn’t worry. I would verify magnesium is in the proper range though.

 

[blasterman]

Calcium by content is at much, much higher levels in sea water than alkalinity. So, even though alk and calcium are typically consumed at a fairly defined ratio by corals alk will always appear to fall much faster.

Next, a 110gal tank, unless it's stocked heavily with SPS won't need much calcium dosing, if at all. In fact, the 10% water change should easily suppliment what is being consumed. Calcium, unlike alkalinity has a fairly wide tolerance range and there's no reason to test it constantly.....unless you have a tank stocked heavily with large growing SPS...which you likely don't. Also, I've never seen a reason to keep calcium over 400. You want stable alk, but stop worrying about calcium. In a tank that arge with smaller SPSfrags the only reason it will drop much is if you grind alk too high.

Alk will falll faster than a normal ratio with young tanks because alkalinity is consumed by bacteria colonies as the tank matures. I've seen smaller tanks eat 1-2 points dKH daily as they mature. At a point of tank maturity this will stop, typically abruptly.

 

[Randy Holmes-Farley Verified Community Expert]

What exactly are you dosing and do you use tap water or do water changes?

How many dKH per day are you dosing of alkalinity?

 

[galantra]

thank you all for the replies in regards to my question.

currently I am dosing BRS 3 part solution. But soon to switch to Quantum Products
I perform a weekly water change of 10% ( currently looking to change to your 1% daily water change just seeking out how to go about doing with this correctly.)
I use R.O water filter with DI resin

currently I am dosing 17ml split into 2 doses daily

 

[Randy Holmes-Farley Verified Community Expert]

thank you all for the replies in regards to my question.

currently I am dosing BRS 3 part solution. But soon to switch to Quantum Products
I perform a weekly water change of 10% ( currently looking to change to your 1% daily water change just seeking out how to go about doing with this correctly.)
I use R.O water filter with DI resin

currently I am dosing 17ml split into 2 doses daily

Please note I did ask for dKH per day, but I went ahead and tried to figure it our for myself.

Your 17 mL (which I presume is my DIY 3 part using sodium carbonate that BRS sells, but they also sell other versions) only corresponds to 0.22 dKH per day in 110 gallons.

The expected daily calcium decline to exactly match that alk decline is only 1.5 ppm per day. You could not possibly detect that in less than a week, and water changes are likely to confound it so you never reliably detect it.

 

[xtian]

Reef crystals mixes high in calcium which is prob why your calcium is a bit higher. Not an “alarming” level though. As blasterman said, the water changes are likely replenishing it. I’ve never really had to do this for cal but for alk you can test new batch water and current tank water to compare how much it’ll raise the level by. Maybe you can do this for cal? And then you can test at the end of the week or whenever to see how much has been consumed(if detectable) during that period, maybe?

 

[galantra]

the solution is correct that you state Randy

I have been testing weekly on Ca and I have been 2 weeks steady at 484 per hanna checker and before that 480,483. So from what you all are saying

 

[Randy Holmes-Farley Verified Community Expert]

the solution is correct that you state Randy

I have been testing weekly on Ca and I have been 2 weeks steady at 484 per hanna checker and before that 480,483. So from what you all are saying

Then the explanation is the expected drop is very, very small, even if all the alk was consumed by calcium carbonate, and some may be consumed other ways, such as the nitrogen cycle conversion of ammonia to nitrate.

 

[Backreefing]

Calcium by content is at much, much higher levels in sea water than alkalinity. So, even though alk and calcium are typically consumed at a fairly defined ratio by corals alk will always appear to fall much faster.

Next, a 110gal tank, unless it's stocked heavily with SPS won't need much calcium dosing, if at all. In fact, the 10% water change should easily suppliment what is being consumed. Calcium, unlike alkalinity has a fairly wide tolerance range and there's no reason to test it constantly.....unless you have a tank stocked heavily with large growing SPS...which you likely don't. Also, I've never seen a reason to keep calcium over 400. You want stable alk, but stop worrying about calcium. In a tank that arge with smaller SPSfrags the only reason it will drop much is if you grind alk too high.

Alk will falll faster than a normal ratio with young tanks because alkalinity is consumed by bacteria colonies as the tank matures. I've seen smaller tanks eat 1-2 points dKH daily as they mature. At a point of tank maturity this will stop, typically abruptly.

I have seen this phenomenon with high usage of alkalinity in young aquariums myself . And I agree it stops with age . I experienced this in a tank upgrade this year . 37-90 gallons upgrade. Right now my alkalinity is stable at 8.6 . And I haven’t dosed anything in weeks . There should be alkalinity dropping but it’s strangely stable . Lots of sps corals mostly frags but some larger.

 

[Backreefing]

To the original thread I never worry about high calcium. Mine is always 480+ and mag is 1500 .alkalinity is all I Usually check .

 

[Shawn_epicurious]

Please note I did ask for dKH per day, but I went ahead and tried to figure it our for myself.

Your 17 mL (which I presume is my DIY 3 part using sodium carbonate that BRS sells, but they also sell other versions) only corresponds to 0.22 dKH per day in 110 gallons.

The expected daily calcium decline to exactly match that alk decline is only 1.5 ppm per day. You could not possibly detect that in less than a week, and water changes are likely to confound it so you never reliably detect it.

....going with... wow! I hope you area still around in a few months when I finally make it to buying SPS! I am nursing a 4 month old tank and building up equipment right now : )

 

[YumaMan]

This is a valuable post, thank you all for your thoughtful contributions.

 

[Randy Holmes-Farley Verified Community Expert]

I have seen this phenomenon with high usage of alkalinity in young aquariums myself . And I agree it stops with age . I experienced this in a tank upgrade this year . 37-90 gallons upgrade. Right now my alkalinity is stable at 8.6 . And I haven’t dosed anything in weeks . There should be alkalinity dropping but it’s strangely stable . Lots of sps corals mostly frags but some larger.

As I showed above, the OP does not have a case of high alkalinity usage. It is actually incredibly low. So low that he will not readily see the calcium usage.

 

[Randy Holmes-Farley Verified Community Expert]

....going with... wow! I hope you area still around in a few months when I finally make it to buying SPS! I am nursing a 4 month old tank and building up equipment right now : )

I've been moderating reef chemistry forums since about 1991, so it seems likely I'll be around in 4 months. lol

 

[galantra]

Thanks for the insight and the relief that I am not doing anything wrong

 

[Knight_Solaire01]

I have a similar issue, but with my alkalinity. It only goes down by a point or a half point every water change.

 

[Randy Holmes-Farley Verified Community Expert]

I have a similar issue, but with my alkalinity. It only goes down by a point or a half point every water change.

Assuming you mean 1-1.5 dKH in a week or so, that just means hard coral growth is reasonably slow. It isn’t necessarily a problem, depending on what is in the tank.

 

[onetootreefor]

Don’t mean to hijack but a search lead me here.
I have a 130 gallon tank mainly sps dominant

i hve about 6 med-large acro colonies and lots of smaller colonies and frags. im dosing 60ml of brs 2 part. I had a nutrient issue where it bottomed out and tank almost crashed. All corals have revived nothing died. Growth has been stagnant, but getting better. Encrusting portions of acros are growing fast but not many new branches.
Started doing awc 30 gallons a week, feeding heavy, and now my alk is still being consumed at 60ml per day but I have completely stopped dosing calc. Im confused....

 

[I’m Batman]

Totally on this subject in a 20 gallon, about 60 kryptonite candy cane heads, a few montis growing crazy, a few ricordea and a 30+ head and growing acan colony. My dKH sits around 9.5 on hanna checker and calcium at approx 450 red sea pro, mag 1350 average on salifert. Tank setup 7/2017 and rocks are 30lbs figi I've been running since 2011.

My wife got me a galaxea tooth coral, a couple favias, 3 monti frags and a few zoas for Christmas and with in a week my alk dropped to 6.5 dKH. Calcium is within average range.

I'm using B-IONIC 2 part, and for the last couple years 6 drops a week of each keep the 9.5 dKH and calcium within range.

The directions say add 1/ml per 4 gallons but do not say what the increase would result. I moved to 10 drops a week and I'm at 6.8-7.1 dKH.

Question is, approx how much part 1 needed to get back to 9.5?