PH AND ALK SLIPPING HELP!!

[Ikarus5150]

About a week ago I added about a pound and a half of crushed coral to my reef tank. Thinking I might increase biofilter capacity to cover the addition of more coral (running a prism PS not the best). Anyway my ALK and PH have not tested as strongly as usual. My (soft coral) yellow leather and devils hand have not had any polyp extention or expanded as normal. I was doing some reading on this subject and have become spooked.
Could the crush coral be the culprit?
should I take it out?
can I recover? (before things get serious)
*PH= 8.0, *Alk=1.0, NO34= 0 NO2= 0, NO3= 5, *DKH= 7, CA= 450, PO4= 0.25, CO2= 1,8. Temp 80 deg, sal 1.023
40 gal tank, 35 pds LR, 35 pds LS, I run carbon 24/7 changed 1/2 every 2 weeks in hang on filter.
bioload:
squamossa clam. featherduster, Orange cup, several mushrooms, finger coral, devils hand, yellow leather, grn star polyps, brn and grn button polyps, candy cane, frog spawn, hammer, red starfish, grn lettuce nudi, sally lt ft crab, 8 scarlet 6 blue leg hermits, yllw tang about 3"(I will remove when it grows larger),blue damsel.
thanx for your time and interest. ~Mark

 

[Anonymous]

Could the crush coral be the culprit?

Yes. Dry aragonite will act as a seed crystal for Calcium when it's supersaturated like the typical saltwater aquarium. The Calcium will form with two Carbonate ions and precipitate onto the seed crystal. This is what initially lowers your ALK. Magnesium will stop the reaction fairly quickly but the process of stopping the precipitation uses up a lot of Magnesium. This is the secondary problem. With a low Magnesium level you will have a difficult time maintaing Calcium as it will tend to precipitate out of solution again, dragging out moe Carbonate and even more Magnesium.

should I take it out?

Nah. The damage is done and by now it has a bacterial film on it to prevent further precipitation.

can I recover? (before things get serious)

Yep. A few larger than normal water changes over the next week should bring things close to normal. You'll want to test for Magnesium to make sure it comes back up with the water changes.