Big picture, what’s new?

Overall, in our opinion, not much.

Still fish and corals in a glass (or acrylic) box filled with water.  For the animals to survive and thrive, the goal is “clean”, balanced saltwater and the strategy as we see it remains the same, water changes.

The frequency and amount of change depends on your bio-load, your acceptable loss policy, and budget (time and money).

For us, the sweet spot was 10 to 20%, every week or two.


Water chemistry

For those following our KIS system, you will remember that the idea is to remove and/or turn-off every gadget and gizmo possible.

Also, we don’t “test” the water all that carefully.  On occasion, we check salinity and pH.  Nothing seems to vary and the Big 3 (ammonia, nitrates, nitrites) are always zero.  Temp reaches 80 in summer and 74/76 in winter.

We do a 7 to 10% water change weekly. Big external fuge with a gob of chaeto, a low bio-load, and “easy” critters in a mixed reef.

Everything has always survived.  Survived but maybe not thrived is the way to put it.  No additives of any sort though.  Consistent water changes and RODI top off of about a gallon per day.

What has not done well for us — zoas.  For whatever reason, the few we tried have not really opened all that well and appear to be elongated as if reaching for the light.  We have tried different lights, changing salinity, and different tank locations.
No luck, so we really don’t try any longer.  Like many aspects of this hobby – who knows?  We do have one basic green zoa that has been “surviving” for many months now as described above.

Remember LFS2?  While there, we are talking with a tech about best practices and both of us mention that we don’t use auto-top off.  Anything that can leak, or flood, or overflow we both agree should not be used.  In general, we don’t like  to leave water running anywhere.

Now, the tech mentions in passing the key words that hit us with the a-ha moment, we know it, but we don’t yet see it clearly.  For some reason,  the tech says, RODI has “zero pH”.  Why he mentioned that, we don’t even know.

The LFS2 comment still in our heads.

We test our water again. Somewhere between pH 8.2 and 8.4 on the card but hard to read.  Not an exact match on the color card for 8.4 but very close.  Or is that wishful thinking?

So we test some LFS2 water from the wrasse bag.  A-ha.  An exact match on the 8.4 color card.  A clear, translucent popsicle purple.  We hold a pH test vial of our water side-by-side against the white background in full sunlight.  The colors are very different but still our tank water has to be at least 8.2.

We throw one cap full of AquaVitro 8.4 into our system.  It hits the sump with a white flash.  Within the 30 minutes, you guessed it.  Remember  the zoa?  Wide open and vivid green!  The water, always clear, with a recent exception where we had cloudy water in the late afternoons, is now crystal clear– as if there is no water in the tank.

Can a cap full of buffer change 250 gallons for the better in a few minutes?
Can an almost neglible pH difference (lower than 8.4) be the solution to the zoa problem.

OK, we now test our tank and compare it to the reference LFS2 water.  They are now an exact match.

Now, here’s another part of the mystery.  We use the same NSW that LFS2 uses and sells.

Here’s the take-away.  Test your pH, buffer, target 8.4 and no lower, and use a verifiable reference sample.  Don’t rely on your eye to accurately read the card.


Water Testing

Why are you testing?  What are you testing?  How are you testing?

Just start with your fish.  The canary in the coal mine.  How do they look?  How are they behaving?  Look for clear eyes and healthy fins.

If we had to do just one thing — water changes.

Salinity control

Of the many water parameters, salinity is one that we don’t fret over.  We don’t try to fine tune this one.

As  such, in our KIS systems, we have eliminated auto-top-off.  The over arching theme is to simplify and remove sub-systems where something could “go wrong”.

Every day or so we throw in some fresh RO/DI water.  After some observations and rough calculations, we figure we lose about a gallon of fresh water per day to evaporation.

We test with a refractometer and the salinity bounces around between 1.25 and 1.27.