Reef Mentoring: Part 9 – 4 Month Tank Update

by | Mar 11, 2023 | Tanks | 0 comments

Preface: This Reef Mentoring article series is to document my recommendations to a hobbyist I have been mentoring. I am basically building a reef tank with his setup in my house and maintaining it for a year with weekly hands on sessions.

Since the last update we were dealing with some of the typical ugly challenges in a nano reef system.  This included some cyanobacteria outbreaks, low nitrates, and mysterious fish deaths.  Fortunately things have positively progressed and I will detail some of the solutions used to deal with the issues.

Problem: Cyanobacteria

Every hobbyist will encounter cyanobacteria and there is a lot of online content discussing it. The key is keeping your tool box prepared since cyanobacteria will always creep up on occasion.

Solved:  Below were my actions that dealt with this issue.

  1. Vacuum gravel with 30% water change
  2. Added additional Clean Up Crew (Astrea snails, cerith snails, and tiger conch)
  3. Nuclear Option was to add a bit of ChemiClean for 3 days

Problem: Low Nitrates ?

The API Nitrate Test Kit in the Reefbot I was using repeatedly produced 0 ppm results which was odd. Though the reagent container was not expired, I had my suspicions and luckily I had a Nitrate test kit on my main system Reefbot and a new kit in box to compare it to.  When troubleshooting titration tests, always compare automated results to manual results. In this case, Reagent #1 was bad in both multiple automated and manual tests.  The other 2 sets of reagents both tested consistently to each other, automatically and manually, multiple times.  I have had issues with specific batches of other branded reagents as well so this is not a new issue with hobby-grade test kits. The key is to record the lot numbers and keep a proof of purchase for the reagents and report them back to the manufacturer; they usually will compensate for the bad batches.

Solved: With the root cause being the bad reagent, I stopped nitrate dosing, and performed a large water change to re-baseline the water parameters.

Problem: Mysterious Fish Deaths

Four out of the 6 original fish mysteriously died after being in the system for about a month.  The only thing I can think that may have introduced something externally was the addition of the new clean up crew.  It was tough to determine what it was, but the symptoms showed up externally on all fish except for the 6 Line Wrasse. It did not look like Ich though.

Solved: In addition to the large water changes and the reduced nitrates from the issue above, I added a UV sterilizer to the filter chamber. After a week, the white spots on the Oscellaris clownfish disappeared and its appetite returned.  It may have been some bacteria in the system that the UV sterilizer helped control in the water column.  I run over 120 Watts of UV on my main system 24/7 and have not had any fish ailments in a long time so that may be a good practice in general.

New Additions

Fish – Starry Blenny to aid in algae control

Soft Corals – More Discosoma mushrooms and a Rainbow Bubble Tip Anemone

LPS – Candy Cane coral, Hammer coral, and NY Knicks Torch

SPS – Milka Stylophora, Cherry Blossom Montipora,


I’m glad that these issues are past us – the system is running well and the corals are showing polyp extension and growth.  The challenge that remains in all my systems is the pH swing between night and day that seems to be a different schedule during the cooler months vs. the warmer months. I’m not too worried as long as the average remains at a pH=8.3.  I will have to keep playing with the calcium hydroxide dosing regimen to see what it needs to flatten the curve.

  • Ellery Wong

    Ellery is a mechanical systems engineer at a Fortune 500 technology company. He has automation experience in the automotive, appliance, printing and robotics industries as a product development professional but also has over 35 years of saltwater aquarium experience as a hobbyist. He currently maintains a 9 tank / 540 gallon SPS/LPS/Mixed systems. DIY is his forte!


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