Calcium and alk for lps tank

Fishko · Jan 6, 2020

My hammer recently has been a little ticked off and not opening completly my alk was at 11.6 and now has drop to 10.9dkh. My calc was at 450 and now is at 430. Im looking to keep my dhk at 420 for calc and 10.5 for all is this is good for a lps tank. I understand its not good to have fluctuations but will my coral be fine dropping to these levels. My hammer recently has started to open up more my frog spawn is opening maybe at 75 percent.

Also what hanna checker should i get for phosphate should i get the ultra low or the phosphorus. I bought some phosphate rx should come in a few days. Just wondering what the best course would be to test my phosphate. And i know it is unsafe to dose something without testing but when my phosphate rx comes in could i dose a half portion to have peace of mind that my phoshate isnt irritating my corals.

Off topic but will a lawn mower blennie take nori it seems to have mowed down half my algea.

AllSignsPointToFish · Jan 6, 2020

I have quite a few LPS in my tank. I used to run my alkalinity at around 10.5. Over the last three months, I've been keeping it at 8, and everything in the tank couldn't be happier.

I can't comment on the Hanna checker as I use the Red Sea Phosphate Pro test.

And yes, a lawnmower blenny will eat nori on a clip

Fishko · Jan 6, 2020

AllSignsPointToFish said:
I have quite a few LPS in my tank. I used to run my alkalinity at around 10.5. Over the last three months, I've been keeping it at 8, and everything in the tank couldn't be happier.

I can't comment on the Hanna checker as I use the Red Sea Phosphate Pro test.

And yes, a lawnmower blenny will eat nori on a clip

Should i aim for maybe 9.5 then for alk?

dwest · Jan 6, 2020

Fishko said:
Should i aim for maybe 9.5 then for alk?

Any of the alk numbers you quoted will work. But try to keep it stable. I personally would try to keep it near, or just under, my preferred salt mix dKH if I had mostly lps.

AllSignsPointToFish · Jan 6, 2020

Fishko said:
Should i aim for maybe 9.5 then for alk?

Natural seawater has an alkalinity of 7-8 dKH. In my experience, the tank seems to handle drops in alkalinity better that large rises. I can't tell you how much better everything looks once I got alkalinity to 8 dKH and stabilized it at that level.

Randy Holmes-Farley · Jan 6, 2020

Fishko said:
Should i aim for maybe 9.5 then for alk?

That’s a fine alk, but I doubt the higher alk was causing an issue.

huckjai · Jan 6, 2020

I just tested my Alk last night and it was at 7.1 and Phosphates at 0.11. I don't have a calcium tester yet so I didn't test it. I have a torch and hammer coral, both seem to be doing very well. Full polyp extensions on them. I've only had them for a couple months, so can't comment on their overall growth but they seem happy. I assume if I start raising Alk and Calcium, they should grow faster? I don't mind it if they grow slow as I like their current size. Would my Alk at 7.1 still be ok?

Randy Holmes-Farley · Jan 6, 2020

huckjai said:
I just tested my Alk last night and it was at 7.1 and Phosphates at 0.11. I don't have a calcium tester yet so I didn't test it. I have a torch and hammer coral, both seem to be doing very well. Full polyp extensions on them. I've only had them for a couple months, so can't comment on their overall growth but they seem happy. I assume if I start raising Alk and Calcium, they should grow faster? I don't mind it if they grow slow as I like their current size. Would my Alk at 7.1 still be ok?

they may grow faster if alk is limiting them, but others things can too, such as foods, light, or any of many trace elements.

Idoc · Jan 6, 2020

As for your other question... get the Hanna ultra low range phosphate checker over the low range version. Ultra low range has an accuracy of 0.015ppm, low range has an accuracy of 0.04ppm. The ultra low range comes in ppb or ppm versions... get the ppm and you don't have to do any conversions.

Fishko · Jan 6, 2020

huckjai said:
I just tested my Alk last night and it was at 7.1 and Phosphates at 0.11. I don't have a calcium tester yet so I didn't test it. I have a torch and hammer coral, both seem to be doing very well. Full polyp extensions on them. I've only had them for a couple months, so can't comment on their overall growth but they seem happy. I assume if I start raising Alk and Calcium, they should grow faster? I don't mind it if they grow slow as I like their current size. Would my Alk at 7.1 still be ok?

As long as you keep it stable then they should be fine