SPS dieing - is low calcium the cause?

[Hal]

First, some stats: (Salifert kits)

pH = 8.0
sal = 1.026
Nitrite = 0
Nitrate = 0
Phosphate = 0
Ca = 290
Alk = 9.15

20x turnover
Aqua C EV-240 skimmer -pulls out lots of waste
Carbon - in a bag in my overflow until last week. Now running in a dedicated reactor. Rox carbon.
Kalk reactor hooked inline with my auto-topoff. (I hadn't added the media in months, just did so).

2x 250W SE 10K Reeflux bulbs driven by Icecap ballasts
2 VHO Actinic bulbs

My sps corals tend to fade and die. I see cyano growing on some of them periodically, which I blow off. Growth is generally slow. My Idaho Grape monti is growing the best. It's tripled in size in the last two years. Others show slow to no growth. Cyano is a problem on the sandbed.

Chaeto in the sump grows very slowly. I have some feather algae in the main tank that used to grow very quickly, but now seems to have tapered off.

I have numerous Kenya trees and 6-8 good size stalks of xenia that grow well. Some mushrooms that grow slowly, and a green-polyped leather (about 1.5 inches across) that grows slowly but consistently.

Are my sps deaths consistent with low Ca? Or is something else the likely cause.

[Salty Prata]

Hal, that calcium level is very low. Try getting it up above 420 and keep it there. If you can't afford a reactor then go with randy's two part.

[Hal]

I've just started adding Kent Turbo Calcium. I'm wondering whether this will solve my problem, or if there are other causes.

I use IO salt.

[aquariumclown]

From my experience, it sounds like you have some major water quality issues. Here are some things to consider...

- the obvious one, increase CA level
- reduce your light cycle if you have a long light cycle in the display tank, algae thrives on light.
- a large set of cleaning crew consisting of snails and hermit crabs, or even urchins.
- an efficient skimmer for your size tank, usually people who are into sps suggest and oversized one.
- run carbon and/or phosphate reactor


Hope this helps.

[Dejavu]

There could be a few causes. First I would get the Ca levels closer to 420 ppm, turbo ca will do this. Second, if you have Cyano, you probably have excess nutrients. High nutrients can cause this with SPS.

I will assume that you are using RO/DI water for make up water. With a TDS of zero. If so than a few good water changes will help with the Cyano. If your running GFO, it might be time to change it. You might want to tset your make up water and make sure that the Ca levels are 420 ppm or higher. Otherwise you will have a harder time raising it.

Many PO4 test kits will not read lower levels of phosphates. Also if you have Cyano it will use some PO4, giving you a reading that is lower than tested.

[Hal]

<a href=showthread.php?s=&postid=14824067#post14824067 target=_blank>Originally posted</a> by Dejavu
I will assume that you are using RO/DI water for make up water. With a TDS of zero. If so than a few good water changes will help with the Cyano. If your running GFO, it might be time to change it. You might want to tset your make up water and make sure that the Ca levels are 420 ppm or higher. Otherwise you will have a harder time raising it.

Many PO4 test kits will not read lower levels of phosphates. Also if you have Cyano it will use some PO4, giving you a reading that is lower than tested.

I have a 4 stage RO/DI.
Not currently running GFO. I did for awhile but recently switched my reactor to a carbon reactor.

I've been thinking about dosing vodka, but wondered if it was pointless since my phosphate levels test at zero?

[Dejavu]

I would guess your PO4 are not at zero with Cyano. Not say that PO4 are your only problem but just part of it. Ca still need to come up. Most PO4 test kits give a flaws zero IMO. If you have excess to a hanna you will find that the reading is not going to be zero.

I have never dosed vodka, but have read that it will reduce PO4. Water changes is where I would start.

[LobsterOfJustice]

Sounds like a nutrient issue, particularly phosphate, with your mention of cyano and soft corals doing well.

[Hal]

If it's nutrients, then it sounds like I need to start dosing vodka. How do I know how much to dose given that my test kit shows Phosphates = 0?

[Dejavu]

Most people use a hanna. I'm not saying all do, but it might be the best option to avoid a disaster.

[Nanook]

You didn't mention your magnesium level. Low magnesium makes it tough to get calcium levels up.

[Hal]

<a href=showthread.php?s=&postid=14826042#post14826042 target=_blank>Originally posted</a> by Nanook
You didn't mention your magnesium level. Low magnesium makes it tough to get calcium levels up.

That's because I don't have a test kit for magnesium. :D

I don't know that I have difficulty raising calcium as I've only begun trying last night. I'll retest in a week and we'll see where the Ca is then.

[potterjon]

I would test for magnesium before adding calcium. If your mag is low then dosing with calcium will probably prove to be useless, until you raise mag first. Then you can raise calcium. Have you tried a polyfilter?

[Hal]

<a href=showthread.php?s=&postid=14827244#post14827244 target=_blank>Originally posted</a> by potterjon
I would test for magnesium before adding calcium. If your mag is low then dosing with calcium will probably prove to be useless, until you raise mag first. Then you can raise calcium. Have you tried a polyfilter?

I have two polyfilters. Why is it that I should be trying it? To remove phosphates?

Is there any reason to believe that my magnesium is low?

[Nanook]

I bet your magnesium is very low also.

[CeeGee]

I have never had low magnesium while using reef crystals or instant ocean salt. Actually it is always higher than NSW. That being said I would still buy a test kit and test yours.

[potterjon]

A polyfilter may simply pull something out that you dont see or know about.
I think your magnesium is low becuase you dont seem to be able to raise calcium levels. To put it simply, in laymens terms that I can uderstand, your magnesium will steal the carbonate ion from the calcium and not let your calcium bond with it, therefore your calcium levels stay low, until you riase your magnesium levels, the calcium levels will not rise. this is just a guess, I hope it helps.

[revaltion131]

CeeGee, I want the IO you're using. My base, fresh-mixed water tests at 900 ppm Mg with IO. I have had Coral Pro recommended to me by a couple of people. I'm switching when I run through my last bucket of IO, so I can't give you any good input on that yet.

Anyway, I am in agreement that it's a water quality issue. IMO, what you can to do improve things has already been pretty well covered.

[jbird69]

A decent sized water change should replenish your alk, calc and mag levels...to an extent. Most salts have target alk,calc,mag levels that are suitable for coral. I would do a water change and then test 24hrs after. When you do start dosing, start slowly and gradually ramp it. You dont want to make any fast, drastic changes.
I dont think the low calcium is killing your sps. They need calcium to grow, but they can maintain with lower than optimum levels. I agree that something else is amiss in the water.

[LobsterOfJustice]

<a href=showthread.php?s=&postid=14828579#post14828579 target=_blank>Originally posted</a> by revaltion131
CeeGee, I want the IO you're using.

+1, I consistently have low Mg and only use IO/RC

[gaetanocallista]

Finally, you have not stability and with sps is the first step!

[MrPike]

Its strange to me that your alkalinity would be at a good level and your calcium level so low. Have you been trying to increase your PH with a buffer by chance? Or have you been dosing just an alkalinity booster without a corresponding calcium addition?

Either you have been doing the above, or you have low magnesium, you got a bad batch of salt, or your test kit is malfunctioning. You should mix a small batch of salt water and test and see what the results are.

[Hal]

The only additive I dose is kalkwasser as part of my auto-topoff, and as of last night, vodka and Kent's Turbo Calcium. No other buffers, boosters, etc.

It sounds like I need to test for magnesium. I never realized how important it was. Can somebody give me a "heck yeah, everybody should test for magnesium, it's as important as. . ." so I can justify the $30 test kit to my wife?

Do most of you find that you have to dose magnesium? I ask so that I can order that too when I get the test kit rather than have to place a second order. Can you recommend a particular brand of magnesium additive?

[Dejavu]

IO salt is typically low in Mg. IF I have to dose Mg I use Randy's two part Mg supp.

http://reefkeeping.com/issues/2006-02/rhf/index.php

[MrPike]

I would double check the calcium test kit on a freshly made batch of salt first. If it reads low, then you have a faulty calcium test. If it reads correctly then....heck yeah, you need to buy a test and find out where your magnesium is:D