Help please ? with worming fry

[carolerex]

OK, I have spent the last 3 hours scouring the forum looking for answers to my question on how early to start worming fry. No luck so far, so looking for some help on this.
Here's what we have done so far. Babies wormed with Prazi whilst still on parents at 21 days free swimming. Babies moved to thier own 2 foot tank at 23 days. Babies thriving on daily water changes and frequent (5-6 x daily) feeds. Babies now 6 weeks old. No problems so far.
However in the past we have had countles successful spawnings from various parents that have also thrived up until 4 weeks old. After this they would die off a few each day looking like they had gill fluke and even though we treated them they would continue to die off until none were left usually at approx 6 weeks old.
This time we have only lost about 2 runts and one normal size baby so as you can see at six weeks old now, we have done much better this time.
Should we now worm with Big L or are they still too young. They have a tremendous appitite and are looking very healthy and growing well. At this stage they are not showing any symptoms of worms or flukes but as we have read on the forum they can be asymptomatic. We do not want to wait until they get sick and start dying off as has happened in the past.
Can any one give us a preventative worming schedule stating at what age this should commence. By the way all our adult fish are wormed at about six monthly intervals. Thanking in advance for any help you can give us.

[ILLUSN]

Gill flukes are becoming resistant to prazi you'll have better results with potasium permangenate @ 2mg/L for a 2-4 hour bath, this is safe on fry from 4 weeks old (never a problem in my tanks). repeat treatment every 4-5 days for 3 cycles.

[carolerex]

Thanks Illusn, for your help but I have many questions about the method of doing this.
First how the heck do you measure 2mg? We had the chemist weigh up 2grm lots for us, even she could not measure in a smaller qauntity. Also you say a bath for 2-4 hours. Do you transfer them to a seperate container for this? and if so do you add a heater and air stone?
We found this method on the forum somewhere and copied it in case we might need it sometime. This is why we got the Pot Permang measured in 2grm lots. Please advise us if you think this is wrong as we respect your opinion. We are very aware of how careful you need to be while using this chemical and would be very dilligent in observing for signs of stress.
1. Make solution of 2grm to 1 Ltr of RO water (we have RO). 2. Increase aeration. 3. Remove 20% of tank water. 4. Add 1ml of solution per Ltr of remaining tank water. 5. If showing stress fill the 20% of removed water with dechlorinated water. Repeat 5 times every 4 days.
Am I right in thinking that if the water loses it's colour the chemical is neutralised and if that happens before the time is up, what then?
Sorry for all the questions but this batch is so important to us after getting this far and we dont want to make any mistakes.

[DiscusDave]

Thanks Illusn, for your help but I have many questions about the method of doing this.
First how the heck do you measure 2mg? We had the chemist weigh up 2grm lots for us, even she could not measure in a smaller qauntity.

You don't, the instructions you've posted answer your own question :D . You disolve the 2 grams of PP in 1 liter of water. There's 1000 ml per liter, so every 1ml of the water contains 2g / 1000 = 2 mg of PP (assuming it's well mixed).

Either that or you buy lab grade scales for 1K+ :o

[carolerex]

oops! Thanks Discus Dave, you can see I am no mathamatition :oops:
I am still hoping to have my other questions to Illusn answered if possible as to dosing in a seperate container or in their own tank

[carolerex]

Since we still have many unanswered questions, we have seperated some of the smaller and not as good ones into a seperate tank and taken the plunge and started the treatment on them, this way we are not risking the whole lot if we make a mistake. The main bunch are still thriving. The treated ones after one dose are also looking OK at this stage.

[ILLUSN]

sorry for the late reply.

my method is to disolve 2g of pp in 10ml of water, store this in the fridge its good for a month.

add 1ml of ths solution for every 100L of tank water (so 1ml in 100L, 2ml in 200L, 0.8ml in 80L etc etc etc) this will give you a final conc of 2mg/L.

i treat my fry in their tank, i remove the sponge filter and sit it in a bucket of tank water, i replace the sponge filter with an airstone in the main tank and just dose, that way you not only kill all the flukes on the fish but also any in the water column or in the corners of the tank.

once treatment is over i do a 50% water change and put the sponge filter back in, repeat every 5days for 3 cycles, you'll be fluke free.

[carolerex]

Thanks Illusn, that is just what we have done. The only difference in your instructions and the one we copied is in the number of cycles 3 or 5. I think we will go with the 3 you suggested.