ANOTHER Cal/Alk/Mag Thread....

Pastey

New member
Hanna Alk and Cal checkers came in last night and, for the first time, I got results that I trust.

My Alk was 9.6 and my Cal was 404. These both seem reasonable and I was sort of surprised because I just kind of made an educated guess on the levels of kalk to add in my top off water. I currently add 8 tsp of kalk per 5 gallons of top off water so it's not quite saturated yet.

That said, I must now move on to testing for mag and phosphates to see what is limiting growth. I'm trying to pinpoint my lack of LPS and coralline growth which is pretty much non-existent. My pH isn't perfect with lows in the 7.8-7.9 and highs in the 8.0-8.1 range but it's way better than it was pre-kalk which was mid 7's consistently.

While I do have GHA in my tank, I have essentially halted growth since I started dosing vodka and am now up to 4.6mL daily dose level. I plan to hold here for a bit and see how the tank reacts over the course of a few weeks.

I've recently made adjustments to my lighting intensity, duration and spectrum. I've increased the overall intensity, shortened the schedule to make the duration more natural and increased the color spectrum. This was all pretty recent so it's too soon to tell how the corals will react.

Anything I'm missing or maybe should consider? I think I've got a mag test so I'll give that a look tonight but if the test kit is out of date, I'll probably trust it as much as I trusted my other tests before the Hanna checker.
 

bertoni

Premium Member
A phosphate result might be interesting, but problems like this can take some time to diagnose. I doubt very much that magnesium is an issue. If the calcium and alkalinity consumption rate is reasonable, then the magnesium level should be acceptable. Magnesium acts to prevent abiotic calcium carbonate precipitation.
 

Pastey

New member
I wound up having a pretty busy evening so I didn't get a chance to mess with the mag test. I'll have to take a look at that this evening. As for the phosphate test, I don't have a test kit for it so I'll probably just buy the Hanna checker for that when I'm able.

It's not that my LPS aren't surviving because I've had many of the same LPS for a while. It's just that their growth rate is awfully slow/non-existent. I don't really spot feed anything but if the coral is unable to build "skeletal" structure, I don't know what spot feeding is going to do, if anything.

I do broadcast feed LRS every couple of days and my automatic feeder drops NLS pellets in 4 times a day (small amount) so I don't get the feeling that my phosphates are truly out of hand enough to inhibit the growing process.
 

Pastey

New member
Well, assuming my magnesium test was done correctly and is not expired, my mag level is ~1500. I'm color blind so color tests suck hard for me. Any ideas? Iron?? I'm kinda out of my feeding element when I run out of possibilities.
 

bertoni

Premium Member
That number is fine, as are the calcium and alkalinity levels. Other issues to consider would be nutrient availability and lighting. The coralline in your system might require more light or less light, for example.
 

Pastey

New member
"Feeding" should be "reefing". You'd think my phone would know that word by this point.

I'm running a Reefbreeder Photon 48--I know the light is capable, albeit, not the greatest. I've recently made some changes to the lighting schedule and intensity going from a longer, less intense photo period to a shorter, more intense (natural) period. It's an ~ 12 light schedule that peaks around 100% blue/80% white for about 2 hours and then tapers back. Tank is 27" deep and I have zoas about 1/4 of the way up, some LPS on or near the sand bed up to about half way up, shaded mushrooms....

Cliff notes: nothing seems overly lit or receding so I don't get the impression that there is too much light and I know people who have plenty of success with the light.

I am currently dosing 4.6mL of vodka daily. I've had moderate issues with GHA and since I've been dosing 4mL+, I've seen the growth of the GHA halt. If I had to guess (what little that's worth), I'd say my nutrients are on the low side or on their way down.
I'll do a nitrate test this week and report back.
 

bertoni

Premium Member
Well, if you're willing to experiment, I might try reducing the vodka for a bit, on the grounds that the coralline might need more food to grow. That's only a wild guess. The issue might be the strain or strains of coralline in the tank. I managed to kill off the coralline in one of my tanks by switching to much brighter lighting. The coralline never recovered, even after a couple of years. My guess was that the strain I had did not tolerate bright lighting, even though the lighting level was fine and lots of people had coralline growth with similar setups.
 
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