Help w/dropping alkalinity


New member
Hi everyone,

I have a 5-6 week old macro algae tank and am struggling to keep my alkalinity level stable. I am using Kent Nano Reef Part A and Part B.
When I wake up in the morning the alkalinity will be about 2.7 with the kh at 7.5. I will dose the recommended amount and it will bring my levels up to 3.4meq/l and 9.5dkh but by 7-8 hrs later it is back down to 2.7 and 7.5. The light is on for 12 hrs for my macros.

Some other info:

Tank is 12 gallon long (36x9x9)
36"current nova extreme 2 bulbs(one 10k and one pink)
2 powerheads-koralia nanos
Hob filter-aqua clear 30

kh/alk=see above
Nitrates=trace amount (less than 5)

I dose Kent liquid calcium daily and dose the Kent nano reef a/b daily.

I am using 100% ro water and doing 25%water changes weekly

The salt is made by instant ocean


Thanks in advance!


Wrasse Nut
First, that salinty number doesn't look right. Did you make a typo there?

Second, why are you trying to raise it? 7.5 is in an acceptable range.

Third, assuming you don't have anything in your tank which is consuming it that quickly, I'll speculate you're adding it too quickly to your tank.


New member
Yes...typo. It's 1.025.

I was told that my alkalinity should be between 3-4

What do you mean by adding it too quickly? Do you mean I should dose half the amount, wait an hour+, then dose the other half?


Wrasse Nut
The acceptable range is generally regarded as 7-11 dkh.

If you add it too quickly, you can cause a pH spike which will cause the majority of what you add to precipitate out. Same problem of you try to raise it too much in a day. Most people won't raise it more than 1dkh per day.

Regardless, when you dose for it, you need to do it slowly over the course of several hours.


New member
Try dosing your cal and Alk in the same amounts. Not just the Alk portion.

Maybe get a second opinion on your test kits as well. Are they old and expired?

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