Moved 10-gallon Opaeula Colony into the 18-Gallon

The 18-gallon close to the south-facing lanai windows.

Downsizing my opaeula hobby to 2 tanks: 18-gallon & 1.5-gallon. Keeping the 2 that require the least amount of maintenance. The 18 seems crowded, but the opae seem to be fine. I’ve seen a couple of berried females, although they don’t show up in the short video below.

For more on the 1.5-gallon, see “Experimental Oblong 1.5-gal Tank” and “Aqualifter Pump+Filter Change for Small Tanks.” The opae in the 1-gallon tank were also moved into the 18-gallon.

These remaining two tanks are healthy and require very little maintenance. I haven’t done water changes in years. I seldom need to top-off (both are hooded) and salt creep is not a problem. I’ve never had to clean the glass for the 1.5. I haven’t cleaned the 18 glass in over a year. This tank gets a lot of sun, so I may need to do a cleaning of the front panel glass when it gets too overgrown.

I’ve never fed the 1.5. Since combining the 10 and 18 colonies, I’ve been dropping tiny pieces cut from a dime-sized algae chip into the 18 once a week. I don’t think this is necessary since the algae growth in the tank is robust, but they seem to like it.

The 18 is filled to the 10-gallon level to prevent salt creep, and this arrangement seems to be working fine. For the 18, I run the UGF pump for a few hours each day. The 1.5 is still using the Aqualifter system, which runs 24/7 with a very light flow. I may need to clean the tubes when they become clogged, but they’ve been fine so far.

This entry was posted in Uncategorized. Bookmark the permalink.

4 Responses to Moved 10-gallon Opaeula Colony into the 18-Gallon

  1. Mark Uchino says:

    Any idea how many opae are now in the 18 gallon? You’ve been very active for some years raising opae. I’m surprised you decided to downsize.


  2. JimS says:

    Mark, thanks for the comment. Not sure about the combined population. One observation I’ve made is that the overwhelming majority seems to be juveniles and infants. The opae not visible in the video or photo are in the coral condo, and they probably account for a large proportion of the population.

    The process of moving an established colony to another tank was ugly and distressful. I’m sure I ended up killing scores, especially the zoeae and very young who try to escape from my net by burrowing into the substrate. Those who survive the traumatic move also need to adjust to the new and crowded conditions.

    I also added more gravel to the 18’s substrate to increase the biological filtering capacity, and I probably ended up burying scores of small ones who were burrowed in. To add the substrate, I had to dismantle and move the condo, then rebuild it over the new layer of gravel. This process also must’ve killed dozens more.

    This past year, I’ve had less time to spend on opaeula, and the 10-gallon and 1-gallon were beginning to degenerate from the neglect. Salt creep and evaporation was a major problem for both these tanks, so the decision to get rid of them was a practical one. All in all, the change was a harrowing experience for both the opae and me. The removal of the two tanks has reduced the sense of clutter, so I don’t think I’ll be growing this hobby beyond the two remaining tanks.


  3. Anonymous says:

    Mahalo enjoyed reading your post. I have two tanks myself. Good information.


    • JimS says:

      Mahalo, Anonymous. It’s an ongoing learning process for me. I’m not sure if the crowded condition in the 18-gallon is ideal. If not, I’m guessing that breeding will pause until the numbers drop to a sustainable level. If the expanded colony continues to thrive and breed under present conditions, then it’ll be interesting to see where growth will stop. How big are your tanks?


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s