I never shared this story because i thought it was absurd but in 2017 i setup my SPS dominant 115 gallon tank. Since I was just trying to make sure I could keep acros alive I was not as careful about adding frags that had pest. I was for sure mindful but thought I would kill them because of water quality before anything else. Anyways, one weekend we went to Montreal and I went to a LFS that had the coolest looking acro colonies (4" or so) They did not look wild but looking back they for sure where. Everything in the system looked clean so figured i would be good. wrong.
Anyways, I smuggled some corals back into the states, dipped with Coral RX or Revive, cant remember which one and put it on my rockwork (5" away from my tri color valida). I never glued it down just placed it on the rockwork. After 2-3 months I noticed it was not vibrant Yellow. Fearing it was soon RTN or die I fragged it into 5 or so smaller frags and had a few on the sandbed, few on my magnetic frag rack. After a week or so when i observed the frag on the glass rack I noticed clear bite marks - removed the frag and sure enough it had eggs and when i dipped it in freshwater sure enough large Flatworm came of. I removed all the frags in the system from that one colony and decided to just see if they had spread to the other frags in the system.
After my experience I realized AEFW are easy to spot within 2 weeks of the corals being purchased. You can dip a new frag all you want but the bite marks wont show up for 1-2 weeks afterwards.
Lessons to Live by
1. Even if you do NOT have a QT tank, you can catch them on the frag rack withing 7-10 days. If you keep dipping you wont see them. If you see them early in their growth cycle I am 100% confident they will not spread. You just have to trash the frag and consider it a loss.
2. After having a AEFW infected colony on my rockwork (not glued) for 4 months, the pest never spread to the surround acros. They did not mature enough to spread.
3. Once they spread to surround areas you have an outbreak and need to make a decision, live with them or QT them outside of the tank.
4. Dont be a rush to Glue your corals to the rock. Acclimate them and monitor them on the glass frag rack.
5. If the coral has a pest, it will not be evident from day 1, even with dip, the acro frag i had no signs of pest in a dip before, and week later had bite marks.
6. AEFW have evolved with the Acropora species. They have evolved to look like them and feel comfortable only living their short lives on the acropora. AEFW branching out to surround LR is very risky so its good to keep good distant between your frags.
7. QT is best practice but if your not going to setup a QT that can keep SPS alive and well for 2-3 months then your better of buying from a trusted source. I know new hobbyist wont want to do this but cutting of the base with a Dremel or bandsaw is so effective. By doing this you decrease the eggs, which can be hidden from site near the base. If an acro comes back from this they are usually healthy and clean.
8. Only purchase FRAGS. Save the colonies for Aquaculture which tend to cut the frag down to 10 pieces with the assumption only 1-2 will survive.
9. I was able to catch the AEFW because of sites like R2R. If I had not done my research on signs of AEFW I would have not known to trash that corals. I purposely left all my unaffected acros in the tank to observe for few months (without dipping or overreacting) and never seen AEFW in my systems to this date. Months later my tank became a healthy PEST free SPS dominant reef. I looked back and wonder how the hell did they not spread after a 4" Acro Colonie was in my system 4-5 months.