Alk rising on its own?

[HB AL]

So I switched out my 90g with a 180g back in July, all went pretty good some coral losses but all fish did good. I added just 1 bag of sand and quite a bit of some nice mixed limestone and other rocks to alot of old Fiji and other rocks.
I have not had to dose alk once. Checking with my Hanna its maintained around mid to high 8's and today was 9.3. I dose everything manually, at first I assumed corals were not happy but they've been growing well for the last couple months but alk stays steady. I dont do water changes, but this one has me scratching my head. All animals are thriving, here's a vid of the tank. Any ideas would be great.

 

[MnFish1]

So I switched out my 90g with a 180g back in July, all went pretty good some coral losses but all fish did good. I added just 1 bag of sand and quite a bit of some nice mixed limestone and other rocks to alot of old Fiji and other rocks.
I have not had to dose alk once. Checking with my Hanna its maintained around mid to high 8's and today was 9.3. I dose everything manually, at first I assumed corals were not happy but they've been growing well for the last couple months but alk stays steady. I dont do water changes, but this one has me scratching my head. All animals are thriving, here's a vid of the tank. Any ideas would be great.

1. With the larger volume and the same amount of stuff (including the losses) - your alkalinity will rise more slowly.
2. The coral that didnt' die - are likely adjusting - and not growing - and thus not using enough Ak. (this has happened in my tank)
3. There are other issues - lowered nitrate, etc - that can cause alkalinity to rise

I would think just be patient

 

[BanjoBandito]

....dude, that eel is boss. Love it.

 

[HB AL]

1. With the larger volume and the same amount of stuff (including the losses) - your alkalinity will rise more slowly.
2. The coral that didnt' die - are likely adjusting - and not growing - and thus not using enough Ak. (this has happened in my tank)
3. There are other issues - lowered nitrate, etc - that can cause alkalinity to rise

I would think just be patient

Patience is my middle name after 35+ years of keeping the aquatic creatures alive! Thanks for the ideas

 

[HB AL]

....dude, that eel is boss. Love it.

Ya it makes it fun at feeding time

 

[MnFish1]

1. With the larger volume and the same amount of stuff (including the losses) - your alkalinity will rise more slowly.
2. The coral that didnt' die - are likely adjusting - and not growing - and thus not using enough Ak. (this has happened in my tank)
3. There are other issues - lowered nitrate, etc - that can cause alkalinity to rise

I would think just be patient

PS - I meant pH - not necessarily alkaniity (with nitrate)

 

[BanjoBandito]

Ya it makes it fun at feeding time

I see that! Don't see many dragons these days!

 

[nereefpat]

Are you dosing nitrate?

 

[HB AL]

Are you dosing nitrate?

With the amount of food they all eat I do the complete opposite, dosing nopox. Zero nutrients is not an issue. Gonna test again in a while and post some more values.

 

[nereefpat]

With the amount of food they all eat I do the complete opposite, dosing nopox. Zero nutrients is not an issue. Gonna test again in a while and post some more values.

Carbon dosing *can actually increase alkalinity. As nitrates are consumed, the tank is losing H+. I don't know if it's relevant here though.

"FWIW, the alk added is not especially large. The alkalinity gain is 0.8 meq/L (2.3 dKH) for every 50 ppm of nitrate consumed." From RHF.