Why is lower alkalinity preferred?
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SPR1968
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You can set alkalinity at various levels depending on what your trying to achieve but you need to be careful as well.
If your going for accelerated coral growth you can go for up to around 12dKH but you also need to increase other parameters as well.
A good basic guide is around 8-8.5dKH
If your going for accelerated coral growth you can go for up to around 12dKH but you also need to increase other parameters as well.
A good basic guide is around 8-8.5dKH
Letterkenny
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I use this and not sure why it’s so low. I ultimately just supplement it up to 8dkh every time I make a batch.
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Great I’m not alone, new to corals so trying to understand, was thinking I was missing something here.
It’s similar to being told a joke and pretending to get it and not admitting you didn’t understand lol
Really good question, I'm a newbie too and I didn't understand why when I made a fresh batch of salt the alk level was low. Thought it was something I was doing. Thanks for the question and the answers.
Potatohead
Valuable Member
That isn't low really, that's the level in the ocean.
I'm not convinced higher alk helps much at all. I know there has been some research/testing that it does seem to offer increased growth but I believe that is largely a result of higher pH... A tank with higher alkalinity will almost certainly have higher pH as well.
Just through observation my tank is happier with alk around seven, even getting up into the low 8's I notice a decline in my corals. Each tank is different though.
Flippers4pups
Fins up since 1993
@SPR1968 said, the alkalinity that you keep your tank at and the rate in which alkalinity is uptaked is highly dependent upon the maturity of the corals that you have, the amount of coral you have and their health.
The recommendation for most, to keep your alkalinity lower, around 8 dkh is based on the above but also the amount of nutrients you have in your water, your light spectrum and intensity and water flow.
Hobbyists that keep their alkalinity higher can do so if their tank is mature and full of corals that up take the alkalinity. They generally run their light intensity higher and have a lot of flow in their display tank. Why? Because of the health of their corals, the amount of corals and nutrients could spur faster growth with higher alkalinity. This recipe normally does not work very well with new tanks and you will see how new hobbyist complain with a higher alkalinity that the tips of their SPS frags may burn.
So general rule of thumb for new hobbyist is to keep your dkh around 8 and let the tank mature. As you add more Coral and the tank becomes more full, then you can run your dkh at a higher percentage. Once again stability is the key.
Me, I run my tank around 11 dkh, pushing 300 to 400 par at the top of my water line, and have a ton of flow in my tank. My system is now 5 years old and it didn't get to where it's at today from running my dkh very high at the very beginning.
The recommendation for most, to keep your alkalinity lower, around 8 dkh is based on the above but also the amount of nutrients you have in your water, your light spectrum and intensity and water flow.
Hobbyists that keep their alkalinity higher can do so if their tank is mature and full of corals that up take the alkalinity. They generally run their light intensity higher and have a lot of flow in their display tank. Why? Because of the health of their corals, the amount of corals and nutrients could spur faster growth with higher alkalinity. This recipe normally does not work very well with new tanks and you will see how new hobbyist complain with a higher alkalinity that the tips of their SPS frags may burn.
So general rule of thumb for new hobbyist is to keep your dkh around 8 and let the tank mature. As you add more Coral and the tank becomes more full, then you can run your dkh at a higher percentage. Once again stability is the key.
Me, I run my tank around 11 dkh, pushing 300 to 400 par at the top of my water line, and have a ton of flow in my tank. My system is now 5 years old and it didn't get to where it's at today from running my dkh very high at the very beginning.
Thats not low, thats the ocean
I am not at all convinced by the rumors about higher alkalinity helping anything. The main theory about a relationship with nutrients is based on a fundamental misunderstanding of how corals grow.
My own experience has been that high alkalinity kills corals, while they do well at the alkalinity that matches what corals naturally encounter on a reef (~7)
ichthyoid
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Fwiw,
Per Hanna instruments, reefs typically measure 7dKh (125ppm) alkalinity-
Per Hanna instruments, reefs typically measure 7dKh (125ppm) alkalinity-
Last edited:
RMS18
I keep water chemistry as my hobby
I agree with this. You can get Into trouble when running those high dkh much faster than a lower one. I use TM Pro and at 1.026 I get 7.3. I believe from my own experience you get faster growth with a lower dkh but focus on a higher ph. I have tried higher dkh 9-10.5 and didn't see any changes. Since adding a co2 scrubber and running 8.2-8.4 24/7 alk and cal consumption took off and obvious visual growth.
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Thats not low, thats the ocean
I get what you are saying but if the ocean is at 7, wouldn’t that be 7 net alkalinity, a tank starting at 7, then add corals it wouldn’t stay 7 for long...that’s my confusion.
I’m trying to decide between the TM classic and pro, one is 9 and the other 7, not sure if I’m any nearer deciding, thought I was nearly there!
RMS18
I keep water chemistry as my hobby
If I'm understanding your question correctly: Once you add corals they will consume alk, cal and mag. When his happens water changes may not be enough to replenish what was absorbed. Then you will need to dose daily. I use TM Pro on a sps dominant tank and love it. Easiest mixing and cleanest salt I've used, tried 5 others in the past.
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Ok here is where I’m at, I now get it’s easier to start low and dose if needed, I guess people dose the amount the corals use on a daily basis, not so easy to remove if you start with a level too high.
I am going for an LPS reef but if I go for the classic at 9, how do I keep the alk stable? If the corals don’t use much alk, wouldn’t water changes result in big swings? Hope that makes sense.
dbowman5
Valuable Member
ok full disclosure,, i don't get it...
ichthyoid
Active Member
I was going with TM Pro, until I considered this exact dilemma. That’s when I settled on using HW Marine salt. Along with TM, they are also the two brands known to use pharma grade ingredients. I used HW with my very first marine tank many moons ago as well. Both their Reefer & Pro grades run about 9 dKh, which is where I’d like the chemistry to be.
