KCL in tank treatment in a hospital tank for treating AEFW?

helloscroll · Feb 8, 2023

Hello, this is the predicament I am currently in:

I contracted Acropora Eating Flatworms in late 2022 and have been dipping three frag racks full of Acro frags and colonies for the past 7 weeks in Potassium Chloride.

I dipped in 1 TBS Food Grade KCl per gallon for 10 minutes each rack. The first week of dipping resulted in a large number of flatworms being killed. The second week I only seen a couple large flatworms, I haven’t noticed any other flatworms ever since but I continued dipping.

I was about to halt dipping since there all the bite marks have gone away and I haven’t been seeing any in the dips. However last week I noticed about 10 frags still had eggs on them. I also noticed eggs on frags that were not acropora. This led me to believe that the flatworms were surviving in the water column/ glass.

I now set up a temporary tank without fish or rock to hold all the acros and want to use a better method to ensure eradication. I don’t want any chance of the worms surviving on the glass or in the overflow or sump. This leads me with two options:

1. Run the temporary tank with elevated potassium levels for 6 weeks and then reintroduce.

2. Continue weekly dipping and hold the acros in the temporary tank. During each dip drain the entire tank and spray all surfaces with KCl solution. Reintroduce after 6 weeks.

Would option 1 be safe if the only inhabitants are acropora? I have over $10,000 in acros and don’t want to kill them all so I’d want to see what safe concentration people have tried and succeeded with?

Option 2 would leave room for error as I wouldn’t plan on draining the sump and overflow and spraying all equipment as that would be time consuming.

What is the best way to combat these AEFW?

DanyL · Feb 8, 2023

I believe keeping high potassium levels could be risky, see melemv's unintentional experience with it.
Option 2 sounds good, but I want to offer you an option 3 - Praziquantel.

Due to the lack of availability of Bayer, and the riskiness of using KCL, I use it instead as a preventative dip against AEFW, and so far it worked wonders, both preventing me from introducing them to the tank as well as treating infested frags in a temporary hospital tank.

One of the benefits of using Praziquantel is that acros can sit in the dip for fairly long time, I usually leave them in the dip for an hour - hour and half with no ill effects.

While I don't know wether a long term stay in a high concentration of Praziquantel have any effects on acros, due to it's nature of being a muscle-paralyzing drug I believe it should be safe.

The idea to use Praziquantel came from the research below, I think you'll find it as a useful resource

https://researchonline.jcu.edu.au/68053/1/JCU_68053_Barton_2020_thesis.pdf

As for rocks, and other frags - yes, they will lay eggs pretty much everywhere.
One option to eradicate them is exactly what you've already done - removing them from the display.
You also need to follow their reproduction cycle, once a full cycle end and there is no sign for eggs or flatworms in the hospital tank, it should be safe to get them back in.
This unfortunately, can take months.

helloscroll · Feb 8, 2023

DanyL said:
I believe keeping high potassium levels could be risky, see melemv's unintentional experience with it.
Option 2 sounds good, but I want to offer you an option 3 - Praziquantel.

Due to the lack of availability of Bayer, and the riskiness of using KCL, I use it instead as a preventative dip against AEFW, and so far it worked wonders, both preventing me from introducing them to the tank as well as treating infested frags in a temporary hospital tank.

One of the benefits of using Praziquantel is that acros can sit in the dip for fairly long time, I usually leave them in the dip for an hour - hour and half with no ill effects.

While I don't know wether a long term stay in a high concentration of Praziquantel have any effects on acros, due to it's nature of being a muscle-paralyzing drug I believe it should be safe.

The idea to use Praziquantel came from the research below, I think you'll find it as a useful resource

https://researchonline.jcu.edu.au/68053/1/JCU_68053_Barton_2020_thesis.pdf

As for rocks, and other frags - yes, they will lay eggs pretty much everywhere.
One option to eradicate them is exactly what you've already done - removing them from the display.
You also need to follow their reproduction cycle, once a full cycle end and there is no sign for eggs or flatworms in the hospital tank, it should be safe to get them back in.
This unfortunately, can take months.

I had the all the acros removed and isolated on racks but they stayed in the display. No encrusting parts left. But like you said since they will lay eggs anywhere I basically wasted 6 weeks dipping. But I’d like to think of it as a head start. I’ve actually not noticed any ill effects due to the KCl dips, only benefits some increased growth rates and coloration (although this may be due to the lack of flatworms). So I think this may be effective? I have Bayer (Bioadvanced) on hand should I consider interchanging the dips each week?
My hospital system has been running for 2 days and I just added 1/3 of my cheaper acros in there to make sure everything is stable. Over the next couple of days I will move all acropora over and hopefully have my Alk and calcium consumption disled

My plan is this:

Since the acros have been dipped six times I will hope to complete this isolated quarantine in 8 weeks from February 10 to March 31st.

I plan on upping my dose from 1 TBS/Gal to 1.5TBS/Gal (Read that SBB does 2 TBS/Gal).

Each Friday will consist of dipping 3 racks of acros for 15 minutes with light basting each 5 minutes. Draining the temporary tank completely and spraying it and all equipment in the tank down with a slightly stronger concentration on KCl. I’m assuming that the flatworms will not make it past the filter socks. Socks will be carefully changed each Friday.
The tank will be refilled with 50% display tank water and 50% new water.

At the end of 4 weeks I will inspect frags for eggs and am possibly considering remounting three racks worth of acro frags and colonies although I am not sure this is necessary (would love input).

I feel Praziquantel may be a bit pricier than KCl, but I’d appreciate input and corrections to my method. Thank you.