Ca/Mg Levels

[SPotter]

I run a ca reactor with TLF reborn and Zeo mag and no matter what I do I cant keep my ca and mg above 400/1170. Right now all of my corals are in my frag tank and I am trying to get my levels up and stable before moving them back into the DT. I have tested my salt and that comes in at 430/1300 so I know its not my salt. I add buffer to bring the levels hoping that the ca reactor will maintain those levels once attained but within a week the levels drop back down. So, while I want my levels to be a little higher should I really be worrying too much about it?

[hkgar]

A reactor is typically used to maintain levels once established by dosing. Although called a CA reactor what it really does is add (maintain) Alk with Ca as a side affect. I might be wrong and someone will correct me.

Are you having a problem with your alk level dropping? I would dose Ca and Mag to get to the levels you want and then use the reactor to maintain those levels.

[SPotter]

you are absolutely correct about the function of the ca reactor. I have used additives to bring ca and mg up to the desired with the hopes my ca reactor will be able to maintain at those levels but doesnt.

No issues with alk dropping.

[hkgar]

Have you checked the CA level of your media? Maybe it is too low in Ca? You will probably have to dilute the test sample to get a reading. Dilute 1 part test water with 9 parts ro/di water. You obviously aren't getting enough ca in your affluent for the needs of your tank, but apparently enough alk to meet the tanks needs. There are threads on the ratio of alk and ca uptake of corals so you might search for them. I don't know what the ratios are.

[bertoni]

How long does it take the calcium and magnesium to drop? Also, how does the alkalinity level change over that period? Is anything else being dosed? I suspect the reactor just needs to be turned up a bit, but I can't tell.

[tmz]

The media in a CACo3 reactor(Calcium reactor), is calcium carbonate,the same as calcifying organism's skeletal mass. Reborn the product you use claims to be actual coral skeleton When it dissovles it provides 50ppm carbonate to 20ppm calcium ,the same proportion that is consumed by calcifying organisms andwas consumed by teh coral's ,the seletal matter of which is in the product. . Calcium won't be proportionately low. There is no need to test for it and 9 to one dilution method outline above makes no sense to me,at all.
The overall amount a calcium reactor doses depends on how much effluent flows out and how much CO2 enters the reactor dropping the pH which disolves the media. It contributes both calcium and alklanity in the same proportions as consumption . It can easily increase both calcium and alkainity if it's large enough .

I'd set the CO2 regulator and flow to a point where effluent pH was between 6.5 and 6.9 and let it run for a week without other supplements and then test levels in the tank. It won't add very much magnesium so you may need to dose that up to 1280 plus. If the reactor isn't covering consumption you can add two part ( calcium chloride and carbonate in the proper portions , ie 20ppm calcium to 50 ppm carbonate/biarbonate) to supplement it. Commercial two part products come in these proportions or you can follow one ofRAndy Farleys's diy recipees or run some limewater which also provides alk and calcium in the proper proportions.

[tmz]

[QUOTE=hkgar;21252028]A reactor is typically used to maintain levels once established by dosing. Although called a CA reactor what it really does is add (maintain) Alk with Ca as a side affect. I might be wrong and someone will correct me.



As requested ,that is completely incorrect as explained in my earlier post.

[SPotter]

How long does it take the calcium and magnesium to drop? Also, how does the alkalinity level change over that period? Is anything else being dosed? I suspect the reactor just needs to be turned up a bit, but I can't tell.

It takes about a week to 10 days for it to drop. My alk level stays the same and Im not dosing anything else.

[SPotter]

The media in a CACo3 reactor(Calcium reactor), is calcium carbonate,the same as calcifying organism's skeletal mass. Reborn the product you use claims to be actual coral skeleton When it dissovles it provides 50ppm carbonate to 20ppm calcium ,the same proportion that is consumed by calcifying organisms andwas consumed by teh coral's ,the seletal matter of which is in the product. . Calcium won't be proportionately low. There is no need to test for it and 9 to one dilution method outline above makes no sense to me,at all.
The overall amount a calcium reactor doses depends on how much effluent flows out and how much CO2 enters the reactor dropping the pH which disolves the media. It contributes both calcium and alklanity in the same proportions as consumption . It can easily increase both calcium and alkainity if it's large enough .

I'd set the CO2 regulator and flow to a point where effluent pH was between 6.5 and 6.9 and let it run for a week without other supplements and then test levels in the tank. It won't add very much magnesium so you may need to dose that up to 1280 plus. If the reactor isn't covering consumption you can add two part ( calcium chloride and carbonate in the proper portions , ie 20ppm calcium to 50 ppm carbonate/biarbonate) to supplement it. Commercial two part products come in these proportions or you can follow one ofRAndy Farleys's diy recipees or run some limewater which also provides alk and calcium in the proper proportions.

Thanks Tom. I have the MTC Pro Cal reactor and while everyone raves about it I find the fact that it doesnt have a ph probe holder on the lid very frustrating as it makes monitoring the ph level in the chamber very difficult. I need to get this remedied. I tested the output ph yesterday and it is at 7.

If I leave my bubble count at about 1 bubble per sec and increase my flow rate will that help lower the ph level?

[bertoni]

Hmm, that's very strange. I don't know of any way for calcium and magnesium to drop without also consuming alkalinity at the normal rate. Testing issues seem like a possibility, but the situation still seems a bit strange. That's a lot of magnesium to consume in a week. I might skip water changes for a week and test magnesium, calcium and alkalinity every day during that period, to see what's happening.

I assume when you said you were adding a "buffer", you meant calcium and magnesium supplements. "Buffer" usually refers to an alkalinity supplement.

[SPotter]

Hmm, that's very strange. I don't know of any way for calcium and magnesium to drop without also consuming alkalinity at the normal rate. Testing issues seem like a possibility, but the situation still seems a bit strange. That's a lot of magnesium to consume in a week. I might skip water changes for a week and test magnesium, calcium and alkalinity every day during that period, to see what's happening.

I assume when you said you were adding a "buffer", you meant calcium and magnesium supplements. "Buffer" usually refers to an alkalinity supplement.

Whats even more baffling is the only corals in the tank are two very small frog spawn, two med sized duncans and a large piece of rocks with gsp on it so nothing that will really consume ca at an increased rate. I am using Tropic Marin Bio-Calcium supplement to help increase the Ca.

I have questioned my test kit accuracy and I am headed out to the lfs to pick up new kits today.

[bertoni]

The Bio-Calcium contains both alkalinity and calcium, despite its rather confusing labeling. That explains the alkalinity situation. I think the tank just needs more supplement, but I still don't understand the magnesium issue.