My adventures with reef syphilis (aka flatworms) and their elimination. With an exhaustive guide for Flatworm Exit.

[jason the filter freak]

Storytime! (TL:DR, Flatworm Exit worked fine for me. Know what flatworms and other pests look like and look often)

Getting any treatable parasite/hitchhiker/ whatever is a lot like getting an STD/STI: 

1. It takes as little as one slip up to catch it. 

2. It's an embarrassing facepalm moment. 

3. You should inspect the tank you're getting corals from for signs/symptoms. (even a seemly "clean tank" may not be but eyeball it pretty carefully before committing to corals if you can.) 

4. You NEED to let every person you've given corals to and received corals from know you've got it/them. 

5. You need to treat it right away before symptoms get worse. 

15 years of reefing and this is my first time getting flatworms. The person I purchased from didn't disclose he had them (claimed he didn't know). I was impatient one day with multiple stressors and just trying to get out the door. I let the specimen containers float for temp acclimation and then put the frags right in. Big mistake 1. 
 

My usual practice is to inspect all frags with a lighted magnifier, remove all frags from frag plugs (things like flatworms can get underneath the coral between the frag and the surface of the frag plug), and dip them with coral dip, then RODI, then add them to tank. In an ideal world, everyone would have a frag tank to do QT in, but much like a Ferrari many reefers out there lack either the budget or space or both. 

 

I noticed the flatworms later that day. Panicked vacuumed them out after stabbing as many as I could see with a fine pointed scalpel. I thought I got them all. Big mistake number 2. It was at this point I should have gone to an LFS and bought Flatworm Exit or at least started with an order on Amazon. 

 

Fast forward to 2ish weeks later. I'm now starting to see them on the base of all my rock work. Just 5-6 at any given time. The flatworm exit had come in the mail. I had read all the horror stories about Flatworm Exit and was definitely scared. 

In preparation for the treatment, I put together a 20% water change and put fresh carbon* in my reactor and kept it offline. I made an educated guess on my total water volume** and treated with the recommended number of drops erring slightly on overdosing than underdosing.

 

I came back every 10 min to check on the tank and did indeed see the flatworms dying off. They were either falling from the rocks or swinging in the current from some sort of stringy mucus. After 45 min I did a water change with thorough sand vacuuming and brought my carbon reactor back online. After which I kept checking on my tank every 30-60 min for the next few hours (the directions recommend monitoring the tank for 6 hours) after the water change I immediately made up more make up water for another water change in case of a bad reaction (it never came and I'll be doing another water change later this week to not let the mixed water go to waste. 

 

My biggest fears were my inverts. I have two different species of shrimp, 4 different species of snails, 1 species of hermits, and a sea slug. I also have a variety of softies, and one accidental SPS that I've been trying to kill off, and two anems. 4 different species of fish. EVERYTHING DID FINE. No deaths, no sluggishness, everything accounted for and eating the next day. I get that Flatworm Exit doesn't seem to work for everyone and that a single data point doesn't make a scientific study but from hours and hours of reading, I'm pretty sure almost all catastrophic post-treatment issues are user-errors. 

Common user errors seem to be.

1. Waiting entierly too long to treat for flatworms. You should be looking at your rock work at least weekly to check for pests and to marvel at macroscopic life, that's part of the fascination of reef tanks.  If you have tons and tons of flatworms the amount of toxic byproduct will be much higher and more likely to wreak havoc on tank occupants. 

2. Underdosing or overdosing. Follow the instructions. Not what you heard from a friend of a friend who treated one time. Read the instructions and do the math on your calculation at least twice, have a friend check your work.

3. Failure to do an adequate water change INCLUDING sand vacuuming. Flatworms are tiny, you may not see that their bodies are there but they are there do a water change and vacuum your sand bed especially your corners/dead spots. It's important to keep water flow during treatment but if you can try and decrease horizontal laminar flow/flow across your sand bed so the dead flatworms fall to the bottom and don't get blown all over your rocks. 

4. Failure to run carbon* and/or run it properly. If you've got an established reef tank you should own a media reactor period. 

5. Failure to change filter socks or other mechanical media. If you've got a sump system there's a good chance some flatworm bodies are going to make it into your overflow and into your mechanical media. Change your media about an hour after successful treatment and probably 6 to 24 hours later depending on your water overturn and/or how bad your infestation was. 

 

*Carbon: The instructions for the volume of carbon to be used are astonishing (I know I just preached running enough carbon but the amount recommended is HUGE) the instructions recommend something like a pound per 50 gallons. I'm guessing that means old pelleted style carbon, I used Rox .8 carbon and doubled the dosage. I don't have any scientific evidence to back up that calculation but even with 2 largish media reactors, I would not have been able to pack in enough carbon for a pound per 50 gallons. 

 

**Water volume, when calculating water volume there are tons of factors. A "100-gallon tank" doesn't hold 100 gallons, whether you have an all in one or sump the overflow system means that water isn't all the way to the rim of your tank. Don't forget to subtract the volume of water between the rim of your tank and the operating water height determined by your overflow depending on the length/width of your tank this could be a couple of gallons to tens of gallons. Don't forget to subtract water volume in your overflow again could be a fraction of a gallon or a few gallons. Don't forget to subtract water volume displaced by sand/rock work. Sand it pretty easy you again run a LxWxH volume calculation on your sand bed and subtract. Rockwork is harder but you can sort of eyeball the LxWxH volume displaced by your rock. Don't forget to add your sump and equipment volume in. Again a "50-gallon sump" doesn't hold 50 gallons during operation. Make sure you account only for the water present during operation. Some equipment holds a considerable amount of water that's not going to be accounted for in your sump calculation alone. Skimmers, media reactors, algae reactors, etc. Fractions of a gallon to multiple gallons. 

 

Good luck and prevention is key. Learn from others' mistakes so you don't have to learn from your own. 
Happy reefing. 

 

 

 

[treesprite]

Thank you Jason, for the detailed article. 

[VA Reefdog]

Thank you for the info.  Good details to have in an emergency.  Hopefully never need to use it but good to have just in case.

[jason the filter freak]

2 weeks post treatment no flat worms no livestock loss