My brown birdnest in trouble.

[langtudatinh01]

i have pay attention to my birdnest very close since yesterday. some of the branches turned completely white. i found some more area of the colony today. i have this coral for 4 months now. it has double in size since i have it. so i test my water today. PH 8.3, Cal 450, Alk 6.5 (a little low, have been dosing baking soda everyday). salinity is 1.024 and never change. temperature is between 80 and 82. i also have a pink birdnest that doing good. all of my acros, monti, pocillopora and lps are doing fine, colored up, and growth lately. i do have a 3.5" maxima clam (this is the reason i have low alk, i think). the recent addition is the biopellet with a nextreef reactor. i can't quite figure out what goes wrong. please give me some advises, thank you for your help.

routine maintenance: dosing pure baking soda and Kalk daily (have never felt or miss any day for the past 6 months). 15% weekly water change with RO/DI (reading is 0). dont test or dose Magnisium because i do so much water change. I use IO salt and have never had issue with Mag before (tested before). filtration: GAC, biopellets, BM Nac6. my flow is moderate with all the lps are moving. all sps have been growing so i dont think this is the issue. Tank has been up and running for a year and 4 months now.

 

[langtudatinh01]

Does anyone have any advices? thanks. the only think i could think of is temperature. but the tank has been like that the past 2 months.

 

[shroutk3]

Alkalinity Issues did my baseball sized birdsnest in in about 2 weeks. Thats where I would look for your problem. I had switched to oceanic which had a lower walk than my previous salt- Shouldn't have switched.

 

[Norwood IND]

Alk seems low. Are you dosing calcium as well? How much Biopellets did you start out with? I have heard some people have problems when starting out with too much at one time instead of slowing increasing the amount.

 

[langtudatinh01]

thanks for your advices. i understand my alk is low but i dont think a day will cost the birdnest to change. i use Kalk with my top of water daily so my calcium is not change much. i start with 250ml for 50 Gallons just like the recommendation for biopellets (never have cloudy issue). i tested my mag just to make sure everything is ok. my magnesium is way low at 1110 (salifer test kit). i guess the patch of IO salt does not have much magnesium or my corals, clam are using it up quick. Would low magnesium cause this? i think it is the reason my alk is swinging crazy. i have no trouble with PH (constant at 8.3 for the last 6 months).

 

[92Bow]

i think alkalinity too. thats what did my stag