So I recently had an alk spike up to 12 DKH in my 65g system, (normal it's 7-8 DKH) now I know Mark and others will chime in and say 12 DKH is no problem but in my system which is ultra low nutrient, (only a few fish, run GFO, Carbon, filter sock change every other day, skim heavy, feed light, dose bacteria) its way too high and will 100% for sure kill sps. The damage wasn't too bad because I caught it pretty fast so I only lost a birdsnest colony and a yellow - blue tip acro colony, and burnt some tips on most other sps colonies.
I run automated dosers that have been on same dosing schedule for about 4 months. I can only attribute this alk spike to three things/ideas:
1) I had about 5 days before testing at 12 DKH refilled my dosing containers (only done every 3 months) and perhaps my cup measurements were rounded vs/ perfectly flat measured cups making the solution stronger that or my prior solution mix up I screwed that up and it was not strong enough.
2) My sps corals have really taken off the last 2-3 months resulting in almost 3 day visible growth on my larger colonies - like "oh dang that sps is 1/2-1" taller than it was 3 days ago.
3) I probably had not tested alk for 1 month prior to my testing at 12 DKH so perhaps the 2 prior water changes had abnormally high DKH - but I only change 15-20% a month
Is it possible #2 above (in combination with adding more corals, not trimming my chaeto for 3 months) has displaced enough water over the last 2-3 months my overall water volume has decreased resulting in me needing to dial my daily dosing amounts back accordingly? My Ca was actually on the low side 350 when I tested at 12 DKH when I normally target 400-420. I'm sure it is also a possibility that all three contributed not to mention I'm a dumba$$ for not testing my alk more consistently (such an easy test too).
Any thoughts or experiences would be appreciated. My mag was fine at 1450.
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Edited by Bryce - November 07 2014 at 11:46am