Copper/hypo - 28 days? Longer?

[illumnae]

I have a question that's been bugging me. I know I'm missing something but I don't know what.

Basically, we know ttm works because the ich drops off the fish in 3 to 7 days, then takes time to hatch. So long as we finish the transfer every 3 days with the final transfer being after the 7th day, we are clean. Chances of transferring cysts between tanks is practically zero.

This places ttm required time at technically 9 to 12 days. Most do 12 or more, but technically that final transfer on the 9th day is sufficient as the ich would all have fallen off on day 7, and on day 9 the fish goes into a clean tank.

Now my question is, why do copper, hypo and chloroquine need the full 28 or more days to hatch? The water column contains drugs or hypo to kill the pre-encysting protomont or the hatched theronts. So why isn't the recommended time for these 3 treatments also 9 to 12 days? By then all the ich would have fallen off the fish and any protomonts or theronts in the water column already killed. Chances of "riders" are no different from ttm, which us supposed to be negligible.

Not trying to start a fight here, but I'm struggling to see the logic. What am I missing here? Why do we need to wait for the full period for tomonts to hatch?

 

[ThRoewer]

If you do at least 1 transfer at the end of treatment you should be fine after 12 days with medication. Though the medication needs to kill the infective stage.

With hypo you need to do the transfer at the start as hypo especially targets the encystment by preventing the cysts from forming.

Better would always be to do 2 transfers: one at start and one at the end.

Once encysted the multiplying stage can't be killed by anything that wouldn't also kill the fish (bleach, heat, drying). This is the reason why treating in a display tank needs ridiculous long treatment times that overly stress the fish, if not outright kill them.

The best solution is of course TTM and then hold the fish for 3 months in a clean tank while the ich in the DT hopefully dies out due to lack of hosts.
This should even do the trick when a few cysts held out for longer. The clean-up after an ich infection and then 3 months of ich free rest will most likely have immunized the fish against ich (this method had been used in immunization studies with pretty good results).

 

[snorvich]

Now my question is, why do copper, hypo and chloroquine need the full 28 or more days to hatch?

Hypo, copper, and CP only treat the infective stage of the life cycle. The back end of the life cycle is highly variable taking as long as 72 days.

 

[illumnae]

Yes, but by day 7 all the ich has fallen off the fish, and the treated water ensures that any infective stage that hatches early is killed before reinfecting the fish - so if everything has fallen off by day 7, why can't I simply net out the fish on day 7? Where's the residual risk coming from?

It's the same logic as ttm:

Ttm - ich falls off, fish transferred before cysts hatch, fish is safe

Treated water - ich falls off, treated water kills all hatched cysts, fish is transferred once all ich drops off, fish is safe


Unless not all the ich drops off in 7 days, in which case ttm is ineffective; or the treated water doesn't kill all hatched ich before they renfect the fish, in which case treated water is ineffective no matter how long you do it.

 

[illumnae]

I think thr tldr version is why do we need to wait for all the ich to hatch and be killed before treatment is complete? Can't we simply remove the fish once all the ich falls off? Ttm proves that we don't need to wait to be safe, and treated water kills all the ich that hatches between days 4 to 7. Ignore the unhatched cysts and remove the fish after 7 days since the fish would be clean by then

 

[snorvich]

I think you should do whatever feels good to you.

 

[illumnae]

I'm trying to understand the logic here - what am I missing? Why are unhatched cysts ok in ttm but not anywhere else? Simply exiting the discussion isn't very helpful. I know you're one of the foremost experts on ich here. Please help me understand

 

[ThRoewer]

Hypo, copper, and CP only treat the infective stage of the life cycle. The back end of the life cycle is highly variable taking as long as 72 days.

According to Burgess Hypo prevents the protomonts from encystment, which will cause them to die off within hours.
Though it can't kill already existing cysts. That's why a transfer at the begin of treatment is important.
Of course there is also always the possibility to get a hyposaline ich strain that isn't affected at all.

CP is said to kill the parasites even on the fish, so it may also kill the protomonts before they can encyst. Again, it likely won't kill already encysted stages. So again, an initial transfer is key to success.

Copper is just bad because it lowers the fish's immune response. So even if effective against ich, it may open the door for other opportunistic infections that are unaffected by copper. Brook and uronema are such infections that rather benefit from copper treatment.

 

[illumnae]

According to Burgess Hypo prevents the protomonts from encystment, which will cause them to die off within hours.
Though it can't kill already existing cysts. That's why a transfer at the begin of treatment is important.
Of course there is also always the possibility to get a hyposaline ich strain that isn't affected at all.

CP is said to kill the parasites even on the fish, so it may also kill the protomonts before they can encyst. Again, it likely won't kill already encysted stages. So again, an initial transfer is key to success.

Copper is just bad because it lowers the fish's immune response. So even if effective against ich, it may open the door for other opportunistic infections that are unaffected by copper. Brook and uronema are such infections that rather benefit from copper treatment.

Thanks ThRoewer, this isn't exactly my question but it helps. By initial transfer, do you mean the fish is transferred from the lfs bag/qt tank into a clean tank? If so, my intial query is still there.

Tank tranfer us based upon the premise that the fish is removed before the cysts can hatch. The cysts being present with the fish on the floor of the tank doesn't matter as they are non infective.

Now let's look at chloroquine in a worst case scenario. Cysts are present, and the fish have ich on them too. We put chloroquine in on day 1. Any existing cysts that hatch are killed by the chloroquine in the water. Ich that falls off the fish either get killed as protomonts by chloroquine in the water or encyst. If those hatch, they get killed by chloroquine in the water. By day 7 all the ich would have fallen off the fish and it is impossible for the fish to have gotten reinfected during this time for the above reasons. All that is left in the tank at this point is a clean fish and cysts. We established via ttm logic that a clean fish and cysts is safe. So no matter what, 7 days is chloroquine is safe even when starting with an infected tank.

So what i don't understand is that with treated water, be it hypo or chloroquine or copper (ignoring the fact that copper harms the fish too), why are longer and longer periods being recommended when it actually doesn't seem necessary based on the above?

I'm not an expert on ich or biology so i must be missing something - I'm asking for help to understand what I'm reasoning wrongly.

 

[snorvich]

Please reread this

 

[ThRoewer]

You may want to read up on the lifecycle of Cryptocaryon:
Cryptocaryon irritans Infections (Marine White Spot Disease) in Fish by Roy P. E. Yanong (University of Florida)

Marine Ich/Cryptocaryon irritans by Steven Pro

Three Day Transfer Method (after Colorni, 1985)

News from the Warfront with Cryptocaryon irritans:
Part 1, Part 2, Part 3, Part 4, Part 5

Please reread ]URL="http://reefcentral.com/forums/newreply.php?do=newreply&p=24205428"]this[/URL[

That link just opens a reply window quoting your reply.

 

[illumnae]

I've reread all those articles and I understand the ich life cycle. I'm going to try to explain myself again because what I'm asking hasn't been addressed or even brought up in any replies.

1. Tank transfer. The way tank transfer works is after the first transfer into a clean tank, only trophonts exist in the tank on the fish. Over the next 72 hours, trophonts burst out, turn into protomonts that soon encyst into tomonts. Fish are transferred into tank 2 after 72 hours before any tomonts hatch and so in tank 2, again only trophonts exist in the tank. Repeat 2 more times and on day 9, the 4th transfer happens and no trophonts exist on the fish anymore as they all dropped off by day 7 and tomonts are never given a chance to hatch and reinfect the fish (side note: theoretically the day 9 transfer can be straight back into qt or dt as te fish is technically clean at that point. Waiting to day 12 is unnecessary. )

2. Chloroquine. In the treatment tank, the required dose of chloroquine is mixed in and the fish is transferred in. Trophonts exist on the fish and whether tomonts exist is irrelevant. Over the next 7 days, trophonts burst out, turn into protomonts that should be killed by the chloroquine in the water. Even if they aren't, they encyst into tomonts. Any tomites that hatch from tomonts are killed by the chloroquine in the water. Even existing tomonts that hatch into tomites between days 1-3 end up killed by the chloroquine - that's why technically a clean treatment tank is not necessary. By day 7, all trophonts have fallen off the fish and the fish hasn't been reinfected as the chloroquine kills the infective stage as snorvich has emphasized. At this point, if the fish is removed into a clean tank, it is free of ich as any remaining tomonts are left behind in the treatment tank.

What I want to know is where is the mistake in point 2 above? Why is it that in Chloroquine treatment we need to wait for all the tomonts to hatch and be killed? Why is it in ttm we don't? In ttm they never get to hatch, but in Chloroquine we kill all the infective tomites tat hatch anyway so only unhatched tomonts are left anyway so it's the same thing. In both methods if we remove the fish after day 7, aren't they equally clean and ich free since there is no chance of reinfection?

I know it's not comfortable having preconceptions challenged. But please read through this carefully and think through it. If I'm wrong, at least tell me which part is wrong and why it is wrong.

Thank you

 

[illumnae]

Point 2 above applies equally to copper and hypo. Basically the fish is never reinfected in the 7 days as the infective stage is killed. So once all trophonts fall off, the fish is clean once removed

 

[ThRoewer]

to 1. In theory this may be true, but variations in lifecycles of different strains have been observed. So some extra caution is advised.
Also, in rare cases Cryptocaryon may encyst on the fish itself (or on another fish in the same tank). While unlikely, it is a possibility that can't be ruled out, especially not in the confines of a rather barren QT. This is one of the reasons why I would combine TTM with hyposalinity if I wanted to be extra sure not to get ich into a system (it's in mine so I don't care too much).

2. should in theory work too, which is why I would advise to combine any treatment wit at least 2 transfers (in and out of the HT). Again, the extra days are too be sure everything is gone and to account for possible variations in lifecycle.

The long treatment periods come from the assumption that you treat inside the display tank where preexisting cysts are present that can hatch for a period of up to 11 weeks (according to current knowledge). I think the reason that the actual treatment time on the products is usually shorter comes from past knowledge of the ich lifecycle - before the long term encystment was discovered.

 

[illumnae]

Thank you very much ThRoewer! Your response was exactly what I was looking for. I was really very puzzled about where I was figuring things wrong for point 2. Thank you for your patience and explanations