what do you keep your alk at and why?

[flobup]

newb here. just wondering what you all try to keep alk at and why? I have a basic understanding of reef chemistry but alk levels are some what confusing to me because of the wide spectrum that are acceptable levels.

im asking because my hammers have been acting up and I think it might because of my ALK. when I put them in my alk was 9.3 and when I did my water change a week later it was 8.7. got it back up to 9 and they seem to be doing a little better.

 

[MissyTwitch]

I run a mostly acropora tank. I try to keep my alk 9-10. Anything less than 8.5 causes stress in my tank, less than 8 causes RTN. Mostly cause my Alk sits continuously at 9-10. Swings up to 10-12 don't stress my tank out as much swings down to less than 8.5. A lot of it depends on how stable your system is and where you set your alk at for long periods of time. BRS did a study recently were they had a systems alk up to 12 for long periods of time to see difference in growth and coloration. They had some decent success with that study. Others I know keep their Alk at 7-8 and their system runs just fine. I believe though you'll start to have some difficulties with corals for sure at < 7 and alk >12. Yet, there will always be that one person who states my system runs great at 13 or 6.5.....so what do I know. Mostly, stability is the key. Less swings in your tank the better.

 

[hbrochs]

I’ve seen beautiful tanks with high, medium and low Alk. My tank seems happier with Alk between 7 and 7.5.
I use salt that has Alk right in that range (tropic Marin pro reef). I feel like running a high Alk tank also goes with high par lighting. I also feel that running high Alk exposes you to slightly more to an Alk swing. I could be wrong about this, but just my feeling that running lower Alk is a little safer. Just my .02

 

[flobup]

my tank is fallow at the moment so low nutrients, with hammers, duncans, zoas, and an elegance what would you all sugest my ALK being? its currently around 9

 

[cracker]

Hi Flo, Lot's of OP's out there. It is hard to decide for Beginners like us . I shoot for ALK of eight A little under/over is OK. I'm fairly new to this & Folks say their tank's look best at this or that level. I don't have that "looks best"
knowledge yet. May I suggest choosing a number & work on keeping it there (stability) . Let us know what You decide .

 

[DivingTheWorld]

People run Alk at different levels and there is no right answer, just what works for you and your tank. My acro tank does best between 7-8. There is a theory that tanks with lower nutrients (phos/nitrate) do better running lower Alk and tanks with higher nutrients do better running higher Alk. I run my phos/nitrate at 0.05/5 and my acros do well with A LOT of light. I was originally running higher Alk of 9-10 and my acros did much better when I dropped it.

 

[flobup]

ok thanks for the replies all. ill try and drop my ALK to around 8.5 or so within the next 2 weeks. and on a side note ive never measured my phosphate levels. should probably do that lol

 

[Tamberav]

Alk 7-8 seems to be the sweet spot for me. Low nutrients.