Sharing a Lesson Learned with KH Director


Active Member
View Badges
Nov 13, 2017
Reaction score
Thought I'd share this experience:

So I'd been having a little trouble with consistency on my KH Director. I'd recalibrated and recalibrated to no avail.....

I decided to check something and found a piece of valonia/bubble algae in my sample tube. It's clearly been there a while, and whilst growing it'd been adjusting the flow restriction on the tubing...

In particular, I was seeing large drops in KH in the evening and overnight - but that's not what was happening, I am now assuming that the sump lighting was causing the bubble algae to inflate, and as such was restricting the flow further at night.

Replaced the sample tube and it's been rock solid for a week, in line with Salifert manual testing.

As expected, the issues were user error, and the equipment is spot on as ever!

Is your current reef tank the BEST reef aquarium you've ever had?

  • Yes

    Votes: 261 70.7%
  • No

    Votes: 78 21.1%
  • It's a tie

    Votes: 11 3.0%
  • Other (please explain)

    Votes: 19 5.1%

Online statistics

Members online
Guests online
Total visitors