Optimal Alkalinity Level?

TangsRLife · Feb 3, 2017

So for around 5 months I've been keeping my alk at around 8.3-8.5 dKh. I slowly increased it up to 9 dKh and I've been holding it there for around 2 weeks now. I noticed my pH has gone from topping off at 8.10 to 8.18. I've read many forums and sources that an increased pH up to 8.3 causes an increase in coral growth. Is this true? Can I raise my alk up to 10 or so and see a increase in growth or is this not the way to go?

Catchemall · Feb 3, 2017

Watch your nutrients as you raise your alkilinity. Higher the alkilinity the higher the nutrients need to be. If you have a high alk level and low nutrients your going to see a lot of unhappy coral. The faster they grow the more they need to eat

TbyZ · Feb 3, 2017

Catchemall said:
Watch your nutrients as you raise your alkilinity. Higher the alkilinity the higher the nutrients need to be. If you have a high alk level and low nutrients your going to see a lot of unhappy coral. The faster they grow the more they need to eat

Some people are dosing nitrate & (apparently) see improved coral color.
They then declare that you need NO3 at 5ppm, or higher to be successful, despite the fact that every test kit I have used gives me a zero NO3 reading when I test NSW.

Of course the alkalinity of NSW is only 6.7 dKH - 2.5 meq/l - 125ppm.

I guess if your going to maintain alk at 8, 9, 10 or even 11 dKH you would inevitably need to dose nitrogen.

Catchemall · Feb 3, 2017

I can absolutely agree with this because I've seen it first hand. My tank has always had low nitrate and had phosphate. Which is an imbalance imo one should have more nitrate than phosphate. My corals were suffering so I started dosing stump remover potassium nitrate and try to hold it around 2-5ppm . Immediately noticed phosphate dropped some and coloration took off to levels I've never saw in my tank. Growth is starting to take off as well. My tank for whatever reason likes a alk at 10 so if I don't dose nitrate I see more pale coloration.