Alkalinity and Calcium Consumed?

[dejaco]

System in question is a 210 display with 45 sump.
40 to 45 coral placements (softies, shrooms, zoo's, & LPS)
300 lbs LR and 4 - 6 inch sandbed.
I try to mantain Alk - 200 / 220 ppm CaCO3 and Ca - 420 /450 ppm.
Every eight days now I have been monitoring the drop in levels.
Both values seem to fall 40 to 50 points and then are readjusted up to target levels. Is this normal? Some say running carbon is robbing system; yet still others tell me it's the IO salt I use. Can you switch water for changes to another brand like reef crystals? I had been told not to switch - just stick with one. My addatives for adjusting parameters are Kent's Turbo Calcium and Superbuffer dKH. Just looking for input to make a more informed decision.
Oh yeah the system has been up for 16 months.

 

[big]

I am not and expert by any means, but with IO my calcium dropped like a rock. As soon as I changed to Reef crystals( I think the same company but a different makeup) mine got better with lots of PC's.... Warren

 

[essop3]

Test the IO before your next water change.

 

[bang guy]

Carbon doesn't remove Calcium or Carbonate.
What is your Magnesium level? Temp? PH?
If Mg is low then you will not be able to maintain high ALK & Calcium. Same is true if PH is 8.5. The higher the temp the less Ca and ALK the water can hold.
Why keep them so high? Try ALK at 150 - 175 and Ca at 420 and your pumps will be happier.
Check Magnesium though.

 

[dogstar]

IMO, running carbon and useing IO could be the reasons...Fine to switch brands and slowly do WCs to adjust.....but alk at 200+ and Cal at 450 is going to be hard anyway......those a both higher than needed and will compete against each other to stay there.....

 

[dejaco]

Thanks for the input. I was going off Reefnut's thread in the archives here.
It shows balanced alk and calcium readings. I had been told to keep calcium between 420 and 450; which puts Alk between 150 and 225. So then give me a target range to shoot for and I can see if everything can be kept there.
Overall parameters are :
temp Range from 78 to 79 'F (chiller is set at 78.5 & heaters kick in at night)
SG = 1.023 / 1.024 (depending on top offs)
Ammonia, Nitrite, & Nitrate all zero
pH - 8.3
copper - 0
phosphate - 0.04 to 0.06
Magnesium is an unknown for me, will look for a test kit.
I have always used and liked the results with the Hagen Test kits.
I have taken water samples to our local college chemistry department and to
the municiple water treatment plant and compared Hagen test kit results with theirs and found the kits to be quite accurate. I currently have 1/2 a bucket of instant ocean salt left. Approximately 3 - 4 months of water changes.
So when it's over I will be trying a different salt
Instant Ocean always has a lower Calcium when freshly mixed up (340 - 380)
Alk is also lower - usually in the 100 to 130 range.
Okay I think I have answered what other information was asked for.
So replies needed as to target ranges and if lowered values are simply due to Calcium being utilized by snails, shrimps, corals, algae, etc. Also FYI I have to scrape at least once a week sometimes twice due to Coralline algae everywhere!

 

[dogstar]

I would shoot for Alk. around 180 ppm. and see where Cal. levels out at.

 

[bang guy]

Originally Posted by Bang Guy
Try ALK at 150 - 175 and Ca at 420 and your pumps will be happier.
Already gave a target I think is appropriate.

 

[dejaco]

Okay so Calcium at 420 and Alkalinity at 150 - 175
Thanks Bang Guy
So when it falls next time I raise to those levels. I got that much.
But does this constant falling occur for most reefs or not?
Also if I switch to Reef Crystals will that simply need less boosting,
but still have falling rates?
And if I were to add a calcium reactor to counteract falling calcium levels,
would I still need to keep adding a buffer to keep up Alkalinity.
Wishing I had paid much more attention in all the chem classes now!
This three way entanglement of pH, Ca, and Alk is really not clear to me.
I know that if any one has changed so must the others ie the introduction of addatives.

 

[fender]

If you have LPS, SPS, Clams, Coralline Algae, Halimeda or any other calcium munching entity you will have to add Calcium and Carbonate routinely.

 

[bang guy]

Originally Posted by DeJaCo
But does this constant falling occur for most reefs or not?
Yes but a 40-50ppm drop in a 250 gallon system typically only happens in tanks filled copletely with fast growing corals.
Also if I switch to Reef Crystals will that simply need less boosting,
but still have falling rates?
I predict that if you maintain lower Alkalinity your consumption rate will drop to 10ppm or less per day.
And if I were to add a calcium reactor to counteract falling calcium levels,
would I still need to keep adding a buffer to keep up Alkalinity.
A Calcium reactor is really a Calcium carbonate reactor. It will add Calcium and Alkalinity as well as Magnesium and other trace elements.

 

[dejaco]

Bang Guy "THANK YOU"
Also just counted 41 corals
approximately 92 various snails, 10 shrimp, 40 hermits, plus chaeto in sump.
Looking for more books - any suggestions?