Calc/kH/Alk/Mag partII..Boomer/Bangguy or anyone else..any direction

[phil l]

Out of curiosity, from my low calcium reading went out and got a Salifert Mag test...Tested newly made salt water that had aged 24hrs before I did a water change...
Here are my results...
Newly made water...
Specific Gravity: 1.024
Temp: 80
pH: 8.2
calcium: 360
kH 130mg/L which equals an Alk of 2.6mg/L and a dKH of 7.28 if I did the math right
Magnesium: 1350ppm
phosphate: 0ppm
Water in the main tank...
Specific gravity: 1.024
Temp: 80
pH: 8.2
calcium: 360
kH: 140mg/L which equals an Alk of 2.8mg/L and a dKH of 7.84
phos: 1ppm
I was half expecting my magnesium levels to be low and in turn messing up my calc/alk levels but this doesnt seem to be the case....Anyone have any ideas as to what might be contributing to my low alk and calcium levels??? I was also under the impression that with a low alk level you should see a high calcium level given everything else was normal...this doesnt seem to be the case with me....I am a bit stumped at the moment....I'd like to have a calcium level of 400-450 to promote coraline algae growth and for my inverts for molting and shell growth.
What do you all think...is a calcium level of 360 okay to promote coraline algae growth?? If not, any ideas on the problem and how to correct? I dont want to just run out and buy additives unless I have to....really want to understand what is going on and see if I can correct it naturally...
Just for everyones information, I am using Instant Ocean salt.
The high phosphate level must be left over from my initial cycle, cause I'm not adding any phosphates.....thats a bit baffling as well and a problem for algae growth and stunted coraline algae growth...hoping to get that down to .1 or 0 with water changes and maybe some Phos-sorb.
I have noticed I do have a fair amount of detritis on my sand bed that gets stirred up during water changes....how do you all deal with that? My clean up crew isnt at capacity yet as the LFS didnt have enough crabs. At the moment I have 10 blue hermits, 2 reds, 6 margarita snails, 2 turbos and a cleaner shrimp. Want to add another dozen blue hermits and when I get more algea more snails.
Any input from anybody would be appriciated.
Phil L

 

[bang guy]

My thoughts:
360ppm Calcium with an ALK of 2.6Meq/L and Mg of 1350 is fine for larger tanks where water parameters change slowly just due to volume. For smaller tanks I suggest at least NSW values and preferable slightly higher. B-Ionic or limewater can easily raise your Calcium and ALK levels. I suggest maintaining a balance between Ca and ALK. A good target IMO would be 400 - 420ppm Ca with an ALK around 3.0Meq/L.
As far as low Ca = high ALK, that's not quite the way it works.
ALK for us in the hobby is mostly a measure of Carbonate/Bicarbonate in the water. There are some other ions like Borate but for simplification let's just discuss Carbonate (CO3).
A low Calcium level will not magically create more Carbonate (ALK). Carbonate is used up by calcifying organisms and needs to be added to replenish the supply just like Calcium.
When Carbonate is overdosed it will lower the Calcium level because the Carbonate precipitates with the Calcium and forms Calcium carbonate. This might be where you got the idea that low Calcium creates high Alkalinity. It's the other way around. Also, A Calcium overdose can cause a low Alkalinity for the same reason.
In my experience higher Calcium does not equate to faster Coralline growth. A balanced Ca & ALK combined with very low Phosphate works in my system.
Bang

 

[phil l]

Thanks for the reply...I should have know better on the calcium/carbonate thing...minored in chemistry but its been along time..The tank is a smaller tank 37 high...
Will the B ionic throw my magnesium levels out of whack?...they seem good as they are now.
The phosphate levels are perplexing too....I'm not adding phosphate to the system, so its either left over from my cycle or leaching from something in the tank or added to the tank, like carbon or perhaps food added, or the detritis on my sandbed...hopefully I can get that figured out and lowered thru water changes....
Thanks
Phil L

 

[bang guy]

B-Ionic adds a small amount of Mg but Mg is also consumed, just at a slow rate. I think it's an excellent product for your situation.
Phosphate is ultimately a product of food. PO4 results from the breakdown of proteins. There's no single solution in my opinion. Water changes, Skimmers, algae scrubbers, phosban reactors, etc. all will help. I think a good skimmer and water changes will get you where you want to be as long as you don't overload your system with fish and don't overfeed.