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Old 07/13/2018, 02:42 PM   #1
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Location: stillwater ok
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Alkalinity ok or to low at 7.9?

Current Tank Reads:
Alkalinity 7.9
Magnesium 1400+
PH 8.1-8.3
Temp 77
Nitrites, Nitrates, Ammonia - 0
Phosphate .025

Not currently dosing, just water changes, thinking about adding KALKWASSER to ATO in future, but am unsure since the Alkalinity is 7.9?


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Old 07/13/2018, 02:45 PM   #2
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Sorry, calcium levels have stayed between 450 - 480

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Old 07/13/2018, 02:53 PM   #3
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Seems fine to me. Some people like to run higher to try to maximize sps growth but, personally, I've never really seen adverse effects from low alk, when the alk has been above 7.

Consistency may be as important as the absolute number. If you do water changes every week and your starting alk is 13 and then drops to 7.9 over the week, that's a pretty big swing, even if neither number is inherently bad.

I'd take frequent readings over a water change interval and see where it starts and where it ends before replenishing via water change. If the swing is 'big', you may want to dose kalk. 'Big' likely depends on the coral you're keeping. Some are far more sensitive than others to alk changes.

Some insight into your coral types/density may help people respond but, if you're alk is only dropping to 7.9 over a water change interval without dosing, that strong suggests that you don't have a lot of alk consumption happening in your tank.


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Old 07/13/2018, 03:16 PM   #4
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Ditto. 7.9-9.0 is a good range.


Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low.

Current Tank Info: 105g AquaVim wedge, chromis, royal gramma basslet, starry blenny, chestnut turbo snails, bristleworms, couple of hermits.
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Old 07/13/2018, 07:47 PM   #5
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Alk fine, numbers good, except Nitrate, if actually zero, corals will starve.
Try 2-5ppm a suggestion...

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Old 07/13/2018, 11:54 PM   #6
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A lot of Tanks of the Month have run at pH 7.8. It's a fairly common level for a tank in a house.

Jonathan Bertoni
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Old 07/14/2018, 11:59 AM   #7
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I run my tank around 7.5 DKH just fine but dose for stability to avoid swings.

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