Burnt tip

[awais98]

I have some issues going on.
I am having burnt tips on some corals for past 1 week.
In last one week only major change is I was letting my nitrate go higher to about 4-5 range. It usually used to run 0-1.
I have been feeding heavy lately.

I run ULNS with zeovit.


My Alk has been rock solid 8- 8.5 for many months: no change
Calcium has been solid stable high at 600..... not sure why it’s high but it’s stable at that number for months.
Phos 0-0.001 stable for months.

So my impression is with ULNS, now I increased the nitrate so growth increased and not enough proportional increase in alk. And hence burnt tips, especially on acros that are fast growers.
Am I right?
I know burnt tip happens with high Alk in ULNS, but maybe it also happenes when everything is stable low and suddenly nitrate is increased to allow color and growth?

Ao to decrease Nitrate, what I did was :
1: Changes the zeolite in 5 weeks
2: increase zeolite flow to 400l/hr
3: changed carbon 1 month today.

Hoping to bring the nitrate down again and have the old balance.

The cyano and dinoflagellates issue is same....

By bringing the nitrate back in line, Am I on the right track to fix the burnt tips?

 

[Randy Holmes-Farley]

I'm not sure I see a logical explanation for burnt tips to arise just because nitrate rose a bit (the most likely explanation for burnt tips relates to lack of tissue growth, relative to skeletal growth, due to low nutrients), but perhaps the nitrate rise allowed phosphate to drop lower than usual. Or it could just be coincidence.