KH is low and Calcium High -- how to balance?

[Jetbkk]

I recently added a large quantity of maricultered SPS to my tank (2 weeks ago) and I'm seeing that my KH has dropped from 10.5 to 8.5. My calcium is high at 495. My PH has remained stable at 8 for some time (I'd like that a bit higher but I think 8 is still in the acceptable range).

I have a 230g tank and have been dosing B-Ionic nightly for the last year. Logic says stop the Calcium dose and increase the ALK but I've read that is not the correct thing to do, and that a balanced dose is what I should be doing.

This has me feeling a bit confused how to get my levels where they should be, so I'd appreciate any thoughts on how to deal with this. I've read about baking soda and Kalk, but I wouldnt' dare use either without really understanding how much to use and how often.

Thanks very much for your thoughts!!!

 

[Bearjohnson]

Your dKH is fine at 8.5 and your calcium although a tad high is nothing to worry about. I'd continue what you are doing under the same dosing levels for now and see where you are in the short term provided you haven't upped your dosing due to the addition of the corals, my guess is everything will balance out over the short term.

 

[Jetbkk]

One thing I have not done is check Mag. Do you think low Mag could cause this? I will start testing that asap.

 

[Mike Johnson]

BRS has a calculator and some excellent videos on the subject. I'm not saying that you should go this way, just thought you'd like to peruse the information for a better understanding.

One more thing, I would reduce the recommended daily increase by half of their values stated. Quick changes are never good.

http://www.bulkreefsupply.com/reef-calculator

 

[Mike Johnson]

One thing I have not done is check Mag. Do you think low Mag could cause this? I will start testing that asap.

Having your magnesium level in the high range is a necessity for calcium absorption. Even in the human body and most other living organisms.

So, the answer is: yes, it's very important.

 

[Bearjohnson]

One thing I have not done is check Mag. Do you think low Mag could cause this? I will start testing that asap.

Your mag could be on the low side but again, your numbers are fine at the moment.

I will say that even though you may be doing your water changes regularly, magnesium should always be tested along with the others. If you don't have a test kit, I've found the Elos kit to be one of the simplest to use IMO. ( I hate titration kits) http://www.marinedepot.com/Elos_Aqu...ater_Aquariums-Elos_USA-EO4129-FITKSI-vi.html

I know for whatever the reason, my tank (125g) is a magnesium hog and I add 5mils every day just to maintain 1450.

Side note....Magnesium is a a rather stubborn one to raise. It's not hard to raise it but, it takes several days to bring the level up and maintained. So if you do start dosing, don't rush it. You'll get to where you need to be but, don't be surprised if it takes a lot longer than you thought it would. Bring it up SLOWLY over time

 

[Jetbkk]

Thanks for the suggestions!

 

[sixline]

Here is an excellent article by Randy Holmes-Farley on Solving Calcium And Alkalinity Problems. Just make sure to test, test, test while making any changes. I usually test myself, and then take a sample to the LFS and have them test as well. (Different test kit and different person doing the tests)

Your parameters seem fine for now. What type of salt are you using? I know Oceanic users can tend towards lower alkalnity and higher calcium. I had a similar issue until I switched from Oceanic to Reef Crystals.

 

[PSU4ME]

You need to correct your KH/CA to balanced levels and then dose balanced so I would dose only KH until it comes into balance. As stated, MG in the 1300-1450 range is needed as well

 

[Choff]

Craig Bingman at MACNA talked about kh, CA, mag. It was very interesting. He was strongly a proponent for calcium reactors, with using products like b-ionic etc second and seemed OK with lime water on smaller systems. He was really against using dosing with calcium chloride and baking soda/ash.

He got into the chemistry of how each was broken down, what by products were produced and how inverts and coralline algae used each. I would love to get the power point presentation he used. Kicking myself for not recording it. I did take a few picts..

In the first slide he talked about proper ratios and said you want to be within the green box and on the line. If you were not on the line to adjust one of the other until you were.

Sent from my SCH-I535 using Tapatalk 2

 

[Mike Johnson]

Since the subject is balance, here is a balance calculator.

http://www.ultimatereef.net/info/calculators/alkcalcalc.php?units=9.8&unittype=dkh

 

[Jetbkk]

I'm using Reef Crystals salt, btw. Will start testing Mag as soon as I can get to a store and buy a test kit, weekend at the latest. I've heard conflicting information about just dosing Alk until balanced... so not sure what to do.

 

[Bearjohnson]

I wouldn't "just" dose alk to get balanced however, if you are dead set on exact balance then I'd keep your alk dose at your current level and cut back just a tad on your calcium.

A better plan IMO would be to test your mag to get a complete picture of the water chemistry. Like I previously mentioned, I wouldn't be surprised if your mag was low. Low magnesium makes it hard for your corals to absorb calcium thereby possibly explaining your high calcium levels.

I also use Reef Crystals and I dose mag every day

 

[reefer gladness]

Stability is far more important than a target number, especially for alkalinity. Be cautious while increasing alk, in increase of 1dKH or more per day is enough to chemically bleach some corals.

Low magnesium results in poor solubility of calcium and reduces buffering capacity. I'd be very surprised if your tank doesn't have low mag considering the uptake of alk and calcium, mag is a critical part of water chemistry that many don't learn about until they start having trouble maintaining alk.

If it were my tank, I'd be testing for and increasing mag until it was approx. 3x calcium. I would stop dosing calcium until it drops to around 440ppm and keep mag around 1320ppm. Since increasing mag will increase buffering capacity until it's in balance I would probably dose about 1/2 of the normal amount of buffer until mag stabilizes to be sure it doesn't go up too fast.

 

[yankieman]

I have to give a thumbs up to all the advice given it is right on the money,, I think if you start testing for mag which is a must you will find that once it is in the range you want it the other 2 will balance much easier ,, mine is also a magnesium hog but once i found out that keeping it up to 1350 - 1450 the other 2 "CA/ALK would stay balanced much better,,,, with that said your readings of 8 for alk is not that bad and 495 for CA is a tad high but will come down if you just let it ,,,,,

 

[Jetbkk]

Thanks to all of you for the excellent advise. You are right that many don't know the importance of testing Mag until there is a problem.

I feel much better prepared now to tackle this issue thanks to you all here. I'll update how the Mag looks.

 

[Jetbkk]

Hi Guys --- a lot of my corals have started bleaching out now, some from the base so I have a bit of an emergency on my hands now. I was planning to hit the store and get a mag test kit on the weekend, but I think I'll have to take time off work and do it right away or I risk having a massive die off!

I will post the mag level once I know but things are a bit worrying now. Once things start bleaching can I turn the situation around without losing the corals?

 

[Bearjohnson]

Pick up a small thing of magnesium to dose with while you're out. It won't go to waste

 

[Mike Johnson]

Bleaching from the base? I'd suspect STN or RTN.

 

[Jetbkk]

My Magnesium level is 1130. So it is low but not extremely low (right?)

The instructions on B-Ionic Magnesium say 1.5ml per gallon per day until a target of 1200-1350 is reached. With a 230g tank that works out to 345ml or 11 oz per day! That sounds like WAY too much to me.

Anyone have any thoughts about how much to add?