Strange ALK consumption

[Waters]

I recently rebooted my mature, 2 year old SPS reef. It was filled with fast growing Montis, Slimers, Acros, etc. I removed everything, got new rock and sand, and set it back up. Currently has 6 small Acro frags. I am using almost double the 2part to try and keep the ALK around 8.4.....the same as it was with my mature reef. I have not changed anything except the rock and sand. All equipment, maintenance, salt, etc is exactly the same. Any ideas why this new setup is requiring so much more 2part? Almost forgot...Mg is 1250, Ca is 430, and ALK is around 7.9.

 

[Randy Holmes-Farley Verified Community Expert]

Twice as much is how much in dKH per day? (not mL, dKH)

 

[Waters]

Twice as much is how much in dKH per day? (not mL, dKH)

Thanks for the response Randy. ALK just keeps dropping and I keep increasing dosage amounts lol. I am currently dosing 75ml while the dKH is dropping about .5 per day. My previous setup (which was filled with fast growing coral) I was dosing roughly 55ml per day to keep steady at 8.4. All dosing is Trident controlled, just like last setup. I guess stating it is almost double is a bit of an exaggeration.....doesn't make sense to me though.

 

[Randy Holmes-Farley Verified Community Expert]

The new rock (if dead) and new sand may be acting as seed crystals for precipitation of calcium carbonate.

Here's a copy and paste:

Precipitation is formation of calcium carbonate. It always happens to some degree, especially in new sand because the sand surfaces act as seed crystals for precipitation.

To reduce it, use low pH alk additives and otherwise keep pH on the low side, keep alk low (7 dKH), keep magnesium high, organics and phosphate not too low, and calcium not too high.

 

[Waters]

The new rock (if dead) and new sand may be acting as seed crystals for precipitation of calcium carbonate.

Here's a copy and paste:

Precipitation is formation of calcium carbonate. It always happens to some degree, especially in new sand because the sand surfaces act as seed crystals for precipitation.

To reduce it, use low pH alk additives and otherwise keep pH on the low side, keep alk low (7 dKH), keep magnesium high, organics and phosphate not too low, and calcium not too high.

Ok perfect...thanks Randy. It is new dead rock (CaribSea) and new live sand so that would make sense. My PH is hovering around 7.9 right now. Have to pick up some Mg to raise that. Everything else should be ok.

 

[Waters]

The new rock (if dead) and new sand may be acting as seed crystals for precipitation of calcium carbonate.

Here's a copy and paste:

Precipitation is formation of calcium carbonate. It always happens to some degree, especially in new sand because the sand surfaces act as seed crystals for precipitation.

To reduce it, use low pH alk additives and otherwise keep pH on the low side, keep alk low (7 dKH), keep magnesium high, organics and phosphate not too low, and calcium not too high.

Should have asked this before...how high do you recommend keeping the Mg? I have raised it to almost 1300 but ALK is still steadily falling, even with increasing the per day dosage of ALK and Ca.