alkalinity question

[superparadise]

i have a reef tank, alkanility reading is normally about 100 meg/l or 6 dkh, which is the alkalinity of the seawater i buy from the LFS. Is this too low for corals? I've had the tank for about 3 months and some corals in it which are all doing fine. I've read up on it and get different answers, which will probably happen on here too i suppose.

 

[lordlocks]

i keep mine between 170 and 200.

 

[matt b]

6 dkh is waaaay to low!! it needs to be around 10-12

 

[earlybird]

Originally Posted by MaTT B
http:///forum/post/2494501
6 dkh is waaaay to low!! it needs to be around 10-12
I disagree. Anywhere between 7-11dKH is acceptable.
What are the other readings on the water you purchase?

 

[morval]

sorry to hijack but whats the easiest way to raise dKh?

 

[nietzsche]

yeah it depends. i think 7-11 dKH is good, but i keep mine at 9-10 dKH.
easiest way to raise it is arm and hammer baking soda. baked or not baked depending on your pH. google search: "an improved do it yourself two part calcium" and read up on that. there's also a calculator online to calculate how much to dose

 

[superparadise]

other readings on water are normal
ammonia 0
nitrite 0
nitrate 0
calcium 420
ph 8.4
I have read online that seawater dkh is normaly 6-8 but suggested dkh for reef tank is 8-12, can anyone tell me why this is ?

 

[scopus tang]

Ocean water is constantly moving, and thus chemicaly depleted water is moved out, new water moves in. In an aquarium, we cannot replicate either the amount of available water, nor the movement, therefore, manychemicals are recommended to be kept at a higher level than natural sea water. Make sense?

 

[superparadise]

so your saying i need to have it higher because it will get depleted quicker?

 

[scopus tang]

Yes, alkalinity will deplete rather quickly. Don't exceed the previously posted parameters, but test it weekly once you get a heavy bioload, and you may have to add "alkalinity" in the form of dKH buffer directly to your tank

 

[stonyreef]

I've kept mine ~6.5 - 7.5 dkH, always.

 

[geoj]

Calcium and pH dropping out of the sweet spot for high growth is the reason you would want to keep your dkh up on the high side.