Is calcium this low even possible?

[platax88]

Hi everyone. I have a well stocked 180gal sps reef and just did an alk and cal test for the first time in months. I havent tested do to all my corals always shown great color and PE with moderate growth.

To my surprise Salifert returned 280ppm!!! I have repeated the test 4 times with same results. i am unsure if the test is expired because i got rid of the box.

I've had the system dialed in (so i thought) using BRS 2 part + mag, added via a 3 head dosing pump controlled by an APEX. All three parts have always been dosed at the same rate because as I understand it, if all three elements are balanced then the consumption relation should be equal.

My Alk is at 10.5 (hanna checker) and unfortunately I dont have a MG test at the moment.

If this is an accurate reading, should i not bee seeing signs of distress from my sps at such low calcium? I dont want to rush and dose a large amount to increase before confirming with another kit which i will order asap.

What do you all think? most likely an erroneous test kit?

Thanks!

 

[antbreon]

yes it is very possible mine was there 2 weeks ago ..i have been chasing it for a couple weeks..dropped after a water change...and coulndt get it back up..dosing kalk (lime water) like mad 1 tbs to a gal a day ..in a 90 gal tank..wouldnt come up ...assumed it was because the mag was also low it was..dosing that like mad...got the mag up to 1200 went to 2 tbs a day in the kalk and the cal to 350 ..all the lime water caused the alk to go through the roof 18 it pegged my hanna meter..ph was high like 8.8..kalkwasser wasnt a good solution to the problem..

just got some calcium chloride..so it wont affect the alk ..to get the cal up ...mag was still down to 1200 so more of that..as well added a little vinegar to lower the alk and ph got some buffer without borate because it builds up and adds to the alk..for a kind of false reading.. didnt know that..fun stuff..seems back in line now

it was amazing as soon as i got it back up to 350.. which is still low ..i started to see growth again on my monti's everthing in the tank seems to have faried ok ..i am learning..

 

[scar79]

I would definitely check with a new test kit. Bring a water sample to a LFS and see what they come up with

 

[bertoni]

I agree with getting a result from another kit before doing anything. I'm fairly sure that was a testing error.

 

[platax88]

I tested some IO water and it returned 400 so maybe the kit is NOT faulty. I bumped up calcium 50 points to 330 until i get a new kit to confirm where im at. I'm thinking of trying the red sea pro line. I'm pretty over Salifert.

So dont you all think i should have seens issues with the sps at this low of calcium?

Do you think it will be ok to hover around 350 for a few days?

 

[Ron Reefman]

I tested some IO water and it returned 400 so maybe the kit is NOT faulty. I bumped up calcium 50 points to 330 until i get a new kit to confirm where im at. I'm thinking of trying the red sea pro line. I'm pretty over Salifert.

So dont you all think i should have seens issues with the sps at this low of calcium?

Do you think it will be ok to hover around 350 for a few days?

As far as you could see, it was OK at 280... sorry, I just had to say it. I guess you just showed many of us just why we test rather than just trust the way it looks. It should be fine at 350. Any sps or lps probably won't be growing much, but it shouldn't cause any harm. You really need to get the magnesium test kit as well. As I understand it, magnesium is jsut as important as calcium to your corals, although it isn't used up as fast. :spin3:

 

[feh]

Is it precipitating out? At that level of Alk you should be around 440ppm of Ca to be in balance. I would definitely check the Mg.

 

[Randy Holmes-Farley]

No, it is not precipitating out due to low magnesium. For calcium to drop from 420 ppm to 280 ppm by forming calcium carbonate would require alk to decline by nearly 20 dKH, which there presumably never was in the water.

If the 280 ppm is real, it is either because the OP went along boosting alkalinity and not calcium as corals and abiotic precipitation deposited calcium carbonate, or he used an off batch of salt or has extremely low salinity.

 

[platax88]

Thanks everyone! Ive ordered a new red sea pro cal, mg and alk (just to confirm hanna alk checker)

So assuming i get balanced again. As long as i am dosing equal amounts of BRS 2 part to maintain alk and makeup water matches my params, then both calcium and alk will remain balanced correct? Of course maintaining proper mg levels.

My dosing setup does not allow for individual pump settings so it doses all three at the same rate and this concerns me because i have read that many people are consuming alk and cal at different rates ... I was always under the impression that they were relational and the same dose would maintain same levels in both ... Thoughts from the experts here?

Here are the params i will shoot for:

Alk 9.5 dkh
Cal 400-450
Mg 1380-1400

What do u think?

Oh and btw ive learned my lesson. Weekly testing of the big three on a weekly basis once i get things dialed in!

 

[platax88]

No, it is not precipitating out due to low magnesium. For calcium to drop from 420 ppm to 280 ppm by forming calcium carbonate would require alk to decline by nearly 20 dKH, which there presumably never was in the water.

If the 280 ppm is real, it is either because the OP went along boosting alkalinity and not calcium as corals and abiotic precipitation deposited calcium carbonate, or he used an off batch of salt or has extremely low salinity.

Hi Randy, i use an auto water change system ... And once again, i never test the new 50 gallon batches. Maybe ur onto something here. This brings up a question... Would alk,cal,mg levels drop in a covered 50 gallon brute stored in the garage over 3 weeks?

Thanks!

 

[wayne in norway]

What is your salinity is the number 1. question. I don't think they'll move much in a covered brute, but it depends on what they were in the first place.

While there is a strong (but not unique) relationship between Ca and alk., I wouldn't assume any relationship between Ca and Mg. Normally alk will be used faster than Ca.

 

[platax88]

My salinity in the makeup is 1.026.

Since it is in the garage, it get rather hot though. Do you think this effects alk, ca, and mg

It total water change is of 1.5 gals a day, dosed very slowly throughout the day via a dosing pump.

 

[bertoni]

Very high temperatures could cause alkalinity and calcium to precipitate, but there would be visible signs, like a whitish building on the container surfaces.

If the dosing was off a bit, and that's fairly likely, I agree that the tank parameters might be able to drift to 280 ppm calcium. I hope it'd take a while, though. Were you dosing any pH buffers? They all add alkalinity.

 

[platax88]

Thanks bertoni ... i just get the brownish buildup in the brute that is standard with IO.

What i will do is clean the bucket and mix a new batch. I'll test params then let it sit for a few weeks and retest before taking the auto changer online again.

to answer your question, i dont add buffer

Guys... i think i know what may have happened. I went on a trip to costa rica and apex informed me that I was out of alk, ca, and mg a week into my trip... so the tank was not dosed for about 5 days. Upon getting back I adjusted alk, but i may have not replenished the cal and mg.

I guess its possible to drop that much on a heavily stocked sps tank in 5 days.

Man, lesson learned and i'm glad i did not have a crash. I'm waiting for test kits to confirm before making any other adjustsments, but i feel confident that the 290 reading is correct. I can only imagine what my mg is at now.

Bertoni -- what do you consider the perfect balance of alk,cal and mg for optimal growth?

Thanks everyone!!

 

[bertoni]

I think that as long as the calcium, alkalinity, and magnesium stay in the recommended zones, the exact levels don't much matter as far as growth goes. Theoretically, keeping calcium and alkalinity at the high end (11 dKH and 450 ppm Ca) might help growth a bit, if the organisms aren't limited by some other factor, like nutrients or light.

 

[Randy Holmes-Farley]

Hi Randy, i use an auto water change system ... And once again, i never test the new 50 gallon batches. Maybe ur onto something here. This brings up a question... Would alk,cal,mg levels drop in a covered 50 gallon brute stored in the garage over 3 weeks?

Thanks!

Not enough to worry about, IMO.

 

[feh]

No, it is not precipitating out due to low magnesium. For calcium to drop from 420 ppm to 280 ppm by forming calcium carbonate would require alk to decline by nearly 20 dKH, which there presumably never was in the water.

If the 280 ppm is real, it is either because the OP went along boosting alkalinity and not calcium as corals and abiotic precipitation deposited calcium carbonate, or he used an off batch of salt or has extremely low salinity.

Makes sense.