Do any element of aquaforest can cause STN?

[coburn13]

Hello.

Several pieces of my aquarium have STN on the base.

my tank is 250 liters + 100 l sump.

I dose
3 drops daily pro NP
3 drops of pro bio s daily
3 drops daily pro F
3 drops of AF Amino Mix Monday Wednesday Friday
3 drops of AF Vitality Tuesdays, Thursdays and Saturdays
3 drops daily AF Build
3 drops of AF Energy Tuesdays, Thursdays and Saturdays

My parameters are stable
7.7 kh
CA 420
1300 mg
water changes every 2 weeks with reef salt

what could be happening?

Thankyou and best regards

 

[lynchmob3000]

Bug check!

 

[lynchmob3000]

Stn in my tank comes from alk being too low or dancing around a bit! And it usually happens a week or so after the fact...

 

[Aquaforest]

How long are You using our products?
We don't know anything about Your tank... Can We see photos of that STN? Of Your tank? Of Your sump? Light?Salinity?Nutrients?

Please, give us more details.