Zebra Nerite Snails & Kusuri Wormer Plus

These meds are absorbed into algae and biofilm so that when the snails eat said algae, they are poisoned.

I had to go to great lengths to remove Kusuri Wormer Plus from my tank after I used it to treat camallanus worms, then had to do it all over again when the worms came back/weren't killed the first time and I used Sera Nematol.

What I do whenever I use a med is to run several small batches of carbon for a couple of days each in a small internal filter kept for this purpose. One batch won't get everything as there is an equilibrium between free med in the water and that bound to the carbon. The first batch of carbon adsorbs nearly all of it, then it is thrown away; the second batch removes almost all of what was left, then that too is thrown away. Maybe one more batch of carbon and then I stop using carbon and switch to Polyfilter. Yes it is expensive, but I run a layer of it in my little internal, twice. It used to be made by Underworld, but it was taken over by Arcadia - you may find it referred to by either manufacturer's name.

Then I wait three months, removing any algae that appears on the glass and easy to clean ornaments, and of course doing water changes, before returning snails to the tank. And even then just one at first to see if it gets killed.

It always seems odd to me that shrimps and snails don't seem to be affected by the same things, though thinking about it, one is an arthropod and the other a mollusc so I shouldn't really be surprised.


I had one remaining 5 year old amano shrimp when the camallanus worms appeared. He survived several doses of wormer plus, both the first time late last year then again early this year as I dosed wormer plus again while waiting for the nematol to arrive. But he died within hours of adding the nematol.

Your shrimps seem to be reacting the same way as my amano to the kwp, but I killed a nerite when I put one back too soon. So after using the kwp again then the nematol I did what I described above.
I would definitely clean the glass, and any easily cleaned decor. The shrimps will find food in the hard to get at places - places that snails will also find it hard to get at.

I've had nerties in my tanks for many years, and luckily have three tanks so if I ever need to treat the fish I can move the snails to another tank after a couple of days in a tub of water. And I always keep some polyfilter in the cupboard ready for removing med afterwards. That plus several cleans and water changes seems to do the trick. But because it is so expensive, I use cheap carbon to get rid of the bulk of the med first.

Well, it's been a while since I promised an update. One way and another, it has not been a good winter for me. However things are now looking up!. It is now 9 months since I put the wormer in the tank, and the shrimps are thriving. There must be about 40, and I will shortly be extending the gene pool with a new addition or two.

So, I ran a load of carbon as Sue suggested, and threw it away afterwards. I daren't clean the glass because there are always a lot of baby shrimps on it having "lunch". After 9 months, and many, many water changes, I reasoned that the shrimplets will have eaten and "processed" the copper from the wormer, and the w/c's will have removed it. (Yes, I should have listened!)

I had bought 4 zebra nerites for my 125L, with the eventual intention of adding one of them to the shrimpery, when they had had a month or so cleaning the glass. They did an excellent job. So, one was transferred. For two weeks it hoovered away, doing a sterling job. Then, like before, it slowed down, and spent a lot of time half out of the water, rarely moving. I contemplated putting it back in the 125L, but before I could, and after 3 weeks, I found it on it's back in the tank, not moving, presumably dead. I removed it to a jug of 125L water and waited. To my surprise, after some 6 hours, it had moved a little. The next morning, it was on the side of the jug. It was returned to the 125L, near to the front glass, where I could see it. It very slowly made it's way to the glass, and stayed there for a week. If it moved 3 inches in that time, that would be an exaggeration. I never saw it eat, but it did lay 2 eggs!

Then, it slowly started to move, and feed a little. Now, another week later, it is zooming around the tank, just like before. I think this was a very close shave - either that, or I have been well and truly conned by a pregnant snail! I have ordered some Arcadia Polyfilter (as Sue suggested, of course), and will use that until it's gone. Then, perhaps, I will try one of the other nerites ......... unless, of course ........ you know a better solution?

                                                   Skittler

Wormer plus doesn't contain copper, just the antihelmintic flubendazole; chemical name Methyl N-[6-(4-fluorobenzoyl)-1H-benzimidazol-2-yl]carbamate.

Killing snails is just a side effect of its main function, which is to kill flat worms (platyhelminthes) and round worms (nematodes). It also kills hydra.

No. I had to look it up as well. But I can pronounce it and understand the formula 

Well, I have had a bit of a crisis in the shrimpery. I first noticed that there were no baby shrimps on the glass, which I thought was odd. Then I spotted several dead adults. I immediately did a 30% w/c, and removed the Polyfilter as a precaution. After a few more fatalities, and the remaining shrimps looking a bit sad and inactive, I did another 30% w/c two days later. This tank has been regularly monitored. NH3 & NO2 have always been zero, although NO3 had crept up from 10 to 20 at the last check. I had also been adding a half dose of TNC Lite fertiliser every week, as some of the plants weren't thriving.

I am well aware that "the jury is still out" about shrimp w/c's, with at least one breeder recommending none. However, I have been doing 15-20% about once a fortnight. This made me think about TDS, and the possible effect of the fertiliser, and the increasing nitrates, (and "unmeasureables") possibly suggesting insufficient w/c's. So, I bought a meter - a TDS-3. Although I'm not yet convinced about it's accuracy, if  we assume that it is, and calculating backwards from the current readings for tap water and tank, then the TDS for the tank before the w/c's, could have been about 250/260ppm. This would put it at the top end, or over, most cherry shrimp breeder's recommended limits. With a KH of 4/5, and GH of 6/7, this would already put my TDS around 195-200 (say, 11x17.. Not a lot of room for anything else!

This all started 7 days ago. The tank is now back to normal, and the remaining adults are feeding normally. I also have a few new tiny babies on the glass. I did a 20% w/c yesterday, and I will try to use the TDS meter to monitor the tank as well as the usual parameters. I have decided to stop adding the fertiliser for the moment.

I know that some of us have also had similar "unexplained" losses with shrimps. I hope this helps, but it's only a theory at the moment..........

                                                Skittler

PS Where did that smiley come from? Not me, because I cant! Should read "17.8"

Cool smiley can be written using a number 8 followed by a close bracket, like it's on it's side

Skittler, just to clarify, you did mean to type the 17.8 in the above post and close the brackets just after it? In which case you inadvertently typed the smiley code.

If you put a space after the 8 it works ( 17.8 )
If you don't it comes out (17.

Ah I see what you mean. Apologies. In an effort to bring this back on topic, it's clear you've had a pretty rough time with your shrimpery and I hope the worst is behind you. I will look forward to hearing how you get on in the days and weeks to come. Good luck and I hope you get to the bottom of the issue 

Hello Shrimpers,

Well, its nearly a year now since I added the wormer. I have added 4 new "fire red" cherries, and some additional plants - hygrophila polysperma and affinis. Inevitably, despite a thorough examination, I now have some "hitchhiker" snails. They seem to be coping well. I will leave them for a short while, before returning one nerite to help with the algae. The hitchhikers will then be transferred, as and when, to the assassins in the QT.

I have a quite a few baby RCS of different sizes, so perhaps, after a year, the tank is back to normal?


                                                       Skittler