Laid again with fry just feeding on parents. Good or bad?

[Hooked]

Hi Gang,
I recently took delivery of a lovely Spotted Butterfly pair. I've only had them 11 days but they have laid last night for the third time.
First I should say that I wasn't prepared at all as thought they would take ages to settle in. They were in a tank with another pair that were removed soon after. Also the filtration was a canister with fast flow etc.
The first batch of eggs went within a couple of days of arriving. Within a few days they laid again and 14 free swimming fry has been the result. Amazing considering all the messing around I was doing trying to make their environment better.
The fry have been free swimming for a few days now and are now hanging around the parents feeding off the slime coat. It has been great watching them care for their fry.
But surprise - surprise again this morning. All was going to "plan". I came down, sitting quietly watching the parents care for their fry spitting them back onto the.........eggs?
Its a very large batch of eggs as well, tightly packed together. The last was spread out and only half as much.
I thought the parents would be caring for their young for two to three weeks before laying again?
Everything seems ok, the parents are caring for the fry as before and now are also fanning the eggs etc? Im wondering what probs this may cause? Will the fry eat or damage the developing eggs? (probably eggs are to big?)
Is this normal behaviour? Perhaps the fry's days are numbered as the parents prepare to hatch out the new eggs?
Its a poor pic (did'nt want to set up any extra lights in case I bothered them to much) but you can hopefully make out the fry near the top right of the cone and about half the mass off eggs on the upper right also.


I guess its just sit back and let them get it right in their own good time,

Cheers

[Merrilyn]

The pair must have decided that 14 youngsters wasn't enough, so they have laid again. Most of the time when pairs do this, they will eat the free swimming fry once the eggs are laid. If your pair are still showing parenting toward the 14 fry, you have a good chance of them raising both sets of fry.

Unusual, but it has been done before.

Keep things calm around the tank as much as possible, and just let them get on with it.

Good luck. You have a good pair, and they should give you lots of fry in the future.

[Nev]

Whatever happens now will sort its self out in the long run. Sounds like you've got a great pair!

[Hooked]

Hi Merrilyn, Hi Nev,

Yes I'm very happy with them. I'm "trying" not to peek every 5 mins and am feeding a small amount of black worm every few days. I've found it good because its live food and stays fresh until consumed for days and doesn't rot and need me to be vacuuming the tank all the time, disturbing the proceedings. Other than that I'm doing 10% water changes daily which are done slowly and they don't seem to mind. I'm following your advice Merrilyn and leaving a light on. Mine is a mild blue (low output t5) actinic type light so they can all see what's going on without it being to bright hopefully.
I was hoping to shift them to there 200lt breeding tank before all this but have not had a chance as don't want to disturb them with eggs/fry. They seem happy in my 5ft holding tank for the time being. Its a bit big but they were not waiting around,

Fingers crossed : )

Cheers

[Mrs D]

That's awsome! Good luck with them.

[swampy1972]

I used to just be jealous that you got this pair, now I'm just banging my head against the wall for not having my tank ready to get them :cry:

They'll sort it all out. I doubt having fry a few days apart in age will have much bearing on the outcome for them. If the adults' parenting skills are as good as they would appear I'm sure they'll cope.

The only thing I'd do would be to remove the spawning cone as soon as possible in case they're tempted to spawn again. Though that said, if they're that keen they'll spawn on any surface, but it may just be enough to let them focus on the care of the fry.

Good luck and keep us updated :wink:

[Hooked]

Hi Mrs D,

Love your work! The very best of luck to you to. I'm following your thread with great interest. I noticed that our fish seem to be laying in sync. It got me to thinking that if someone had a bunch of pairs (who would do that to themselves!?), could you sneakily introduce some fry from one pair in with another pairs fry that laid at roughly the same times and have them reared by the other parents? Surrogate parents? .....


Hi Swampy,

Lol, I'm sure you have some AWESOME fish swimming around there at your place!
My spawning cones are $3.00 toilet brush holders from Bunnings. A couple of river stones inside with a couple of cable ties over the opening and hey presto..... Discus eggs!

I have two in the tank, one near each end and noticed they liked to move the first fry from one to the other. Surprisingly they have laid this time on the one closest to where we walk by (Its in the garage, so not walking past to much). I'm not game to remove anything right now.... : )

You guys have a great day!

Cheers

[Nev]

Hi hooked, moving fry from bad parents to good ones makes sense. Can't see how to move eggs but free swimmers would be easy with a syphon. btw i've got 4 pairs, constantly breeding so had already thought of that.

[Merrilyn]

Commercial breeders use surrogate parents all the time. They move desirable fry to foster parents to allow the main pair to lay again more quickly than they otherwise would, if they were rearing their own fry. Obviously their main aim is to produce as many high grade fry as possible, without burning the parents out.

For us, it works well if you have a good looking pair that you are keen to get fry from, but who are confirmed fry eaters. Move them over to your better parents for safe rearing.

So long as the foster parents have fry at roughly the same age, it works quite well.

[Hooked]

Hi Nev, Hi Merrilyn,
I'm sure four pairs keeps you busy Nev. That's about where I'll end up I think, 3 or so good pairs (which I'm sure wont just turn up over night, so I've got plenty of time). With that I imagine they obviously all have there own tank or compartment in a tank, but how many grow out tanks do you find is a good number and what size do you use? I find that 6x2x2 is about the max that I like to shift around and still manage to hang onto my friends! I've been looking for a 6x2x2 to divide into 3 as a breeder and thought of stacking them as grow outs as well in racks. Maybe one divided as the breeders tank and the other three as the grow outs (reinforced thick concrete floors here) for now. I'm just wondering what's a good grow out size and how many fish can be reared in it in a reasonable time to that saleable size (because god knows what I'm going to do with all these Discus if they actually grow otherwise?). : )
I have two 220lt blue plastic drums for my water ageing and they are just keeping up with large display etc as well. Do you have a storage tank instead? I guess a couple of thousand litre is not to big a tank and can spirit it away somewhere.
This is getting expensive? : )
I wonder how many people have been here before me, expanding, only to eventually downsize to one or two pairs due to costs involved?

Thanks Merrilyn for the surrogate info. Very interesting and would be great to try one day. Do you have many pairs these days? Have you ever wondered how many Discus you have helped bring into the world after 35 years?

Cheers : )

[iro11a]

Hey mate congratulations on the pair your purchased i'm very envious of you :D

Personaly i would't have a 6x2x2 split for breeding i would rather have 2 foot tanks for each pairs.I'd leave the 6x2x2 for the growout tank you will be able to get rapid growth with large volume of water,so long as you keep up the water changes.

But i'm guessing you may also want to keep some of the fry for yourself you grow up so maybe a 4x2x2 tank to keep some of your own stock.I'm in the process of expanding tanks(not looking forward to the power bill).So at the moment i only have the one breeding pair in a 2 foot tank.I then had another 2 foot tank to remove the fry into this tank so the fry can still find the food easy doing 100% water change a day 50% in mid afternoon and 50% before i go to bed.I have a 5 footer tank that the fry will go into maybe around 5-6 weeks to grow up and i also have a 4x2x2 which im growing some juvies i got a few months back.Plus community tank inside the house
:)

[Hooked]

Hi iro11a,

all good points, advice and food for thought. Yeah, I'm not looking forward to the future power and water bills! In an attempt to not freak out my wife at bill time I've actually put up an outside clothes line these days and we don't use the dryer any more. We are pretty busy people and had got a bit lazy in that department. Use to have it on 1-2 times a day with kids clothes etc. HOPEFULLY it makes a difference. I do all the clothes washing now too, so its good for brownie points also at new fish time ; )

Cheers


Hi Gang,

I went down this morning to sit in front of the tank and no 14 fry to be seen..... Bummer! :(
Then I got up to take a look at the eggs on the back of the cup.... 1/3 of the eggs were gone and the 14 fry were there burrowing into the eggs! Bigger Bummer! :o
I saw one fry with an egg (way to big for it) grab something on it throw it around then it dropped. Then I noticed all the missing eggs underneath the parents. Oh my god the 14 fry are ripping the tails off the rest....! :shock:
Then after a couple of mins I noticed one wiggle out of the tiny white sack that was left and thank goodness it had a tail! :roll:

All this was a rude awakening.... all before any coffee! : )

It appears that the 14 fry were feeding on the remnants of what attached the eggs and were dislodging the soon to be hatched fry in the process? The newly hatched appear smaller than the other fry at hatch out time? Definitely not as fat and plump looking as Mrs D's pics? But I guess they usually seem to sit and plump up over a few days before free swimming? They don't usually get disturbed from their hatch out spot I suppose?

The eggs on the bottom are slowly hatching out over the day and seem to be finding their way to near the base of the cone? They seem SO tiny. I can hardly see a tail. The parents seem totally unaffected and are just blowing on the newly hatched spreading over the cone itself. I don't know what they are on, but I could use some first thing in the morning!

Cheers

[Hooked]

Hi all,

Over the last 24hrs the 14 fry are now down to about 4 or 5. I can't really see but no way 14 any more of the larger two week old ones. The second lot of fry over the last 24 hours have been rounded up by the parents from around the 400lt 5 footer. They are a week old now. I've learnt a valuable lesson watching last night. The tank is so big that the parents would swim a great distance picking up fry in their mouths. Sometimes up to 10. By the time they got back sometimes only 7 or 8 would be spat out. Its making them work to hard. Hopefully there will be a break in the action soon and I can get them into the proper size tank for hopefully the next batch.
I realise I've made a big mistake also. I used Methlyn Blue to stop fungus but have just been getting rid of it with the water changes. I missed the bit in Merrilyns post about how it inhibits the production of the all important slime coat.
From Merrilyns Breeding basics post;

Quote - "Methylene blue is only used if the parents don't clean their eggs properly, and you're having problems with fungus developing. It's often used by breeders who take the eggs from the parents (as in angel fish) to hatch them in a separate tank. Angel parents are notorious egg eaters and the eggs can be hatched and the fry raised quite successfully on their own. Unlike discus, angel fry don't feed off the slime coat on their parents' body.

It can prevent discus parents developing a proper slime coating to feed their fry, so if you are going to use it, then only use it on the day the eggs are laid, and add carbon to the filter after 2 days to remove all the meth blue, and give the parents a chance to develop a slime coat.

Personally I don't use it on discus. I find that if you lower the pH slightly, to around 6, fungus isn't a problem. - unquote.

I've put in the carbon pad as of this morning and had already been lowering the ph. Its in the low 6's which I believe also helps with the slime coat production. The fry already had been congregating more on the parents with this latest batch as the Meth blue would have been very weak, but today they seem to be swarming the parents and not wanting to take off around the tank so hopefully things are getting back on track and hopefully I haven't stuffed things up to much.

Cheers

[Merrilyn]

It's all a learning experience, so don't beat yourself up too much. New territory for a lot of us too. I've never heard of the older fry ripping the tails off the younger lot. I suppose to them it makes perfect sense. It's just more live food.

Keep posting about your experience, good and bad. This is a really interesting topic.

[Hooked]

Hi Merrilyn,

What I first thought was the older fry nipping the tails off the others was them actually dislodging the newer eggs and feeding on the remnants of what was holding the eggs to the cone. There was like a bald patch in the middle of the egg mass where maybe 1/3 of the eggs had been dislodged with the older first fry feverishly feeding away. Within 24hrs of being dislodged the eggs mostly hatched out and made there way back to and up the side of the cone. There were a few that didn't hatch out that had been knocked to the floor of the tank but I think it was more a case of where they landed was under the parents and I think they got knocked about a bit as the parents fins slid across the area.
I noticed with the first lot of fry that they seemed to hatch out and then stay in the same spot and develop more. The tails were very noticeable before they started moving from their original spot. With the second batch I noticed that the ones hatching out that had been knocked off the cone, seemed really tiny. Their tails were extremely tiny and hard to see.
All fry from both batch's appear to be developing well. The parents stay near the cone and the fry swim across, pick at the parents slime coat and swim back to the cone side.
After checking the dates, the first batch with 5 remaining are about 10mm long by 3-4mm at the head width and actually about 12-13 days old now. The second batch would be 7 days old now and are about 5mm long by 1.5 - 2mm at the head. There's about 80-100 of those but that's my best guess as they are buzzing around way to fast to count accurately.

Cheers

[swampy1972]

Sounds like they're doing well mate, great to hear :wink:

Can't wait to see some more pics as they develop.

[Hooked]

Hi Swampy,

The water has cleared of the Meth now so will try to get some pics later today,

have a good day mate,

cheers

[iro11a]

Great work hooked sounds like things are going really well for you looking forward to seeing some pictures soon.

[swifto]

Good 2 c u got a gr8 pair.Remember 2 keep things simple your doing a job

[Nev]

Looking forward to some pics. :)

[Hooked]

Hi Jon, Rob, Nev, All,

I succumbed to the pressure! : )
I've taken another pic this evening. Its the best after many attempts. Luckily in it you can see all the larger fry, 6 still. A total fluke as usually you can only see 2 or 3. I think the younger fry have been thinned out yet again by the parents, It's really hard to tell conclusively. It gives you an idea of the size difference.
We noticed today that the parents are becoming really protective. When you approach the tank they are not so mellow. One will come out quickly and get between you and the fry. So we have been backing off and leaving them be. They were NOT happy having their pic taken.
Today for the first time I really saw that classic view of a parent swarmed by fry. Both sides covered in a small cloud. Also one is really now giving a good flick of its body when cruising up along side the cone to signal time for a feed.
One thing I also noticed was the first sign of very slight peppering. A few pin pricks of black against the bright white below the dorsal fin. It got me thinking.... I covered my black sponge filter cube in white filter material so as not to have anything in black as recommended so the parents are the darkest thing in the tank. But my fish are white, are highly reflective and the brightest thing in the tank? A bit like the sponge filter...... lol : )


Cheers,

[swifto]

Hi Hooked,they look good.Peppering can b caused by many things,any fish that is pigieon based with dark background and substrait will pepper more quickly,the ph can cause them to pepper up also.I personally think pigieon based discus pepper up more than other discus,but Im no expert. :lol:

[iro11a]

Looking really nice mate. My breeding pair also do the same thing as yours when they don't have fry can clean the tank very easy. Mine also will block my sight so i cant see the fry,i just put it down to good parenting.:)

[Hooked]

Hi Gang,
There's conflict in the tank as of today. I'm not 100% sure which is male and female as I've missed the spawns. But the larger one which I'm guessing is the male and the slightly smaller, less attentive one the female, are lip locking now and again and having a "push me-shove you" over the fry. The larger one happy to attend to the fry and try's to move off the smaller, less attentive one.
I'm thinking mum may want to lay again and if that's the case I'm concerned for the fry. Or perhaps they are fighting over the care of the fry. I've researched and there's opinions over splitting the parents with a piece of egg crate or just leave them be. I'm inclined to at least leave them be, to sort it out on their own and only intervene if the fry start to disappear, if I'm there to see it. If I wake up in the morning and they are all gone I'll kick myself but probably best to let them learn to do it all by themselves? Any thoughts? : )

Its been quiet the last couple of hours. The larger main care giver seems to have won out. The slightly smaller one is right there a few inches away calmly hanging out, feeding some of the fry at times but no where near as popular a feeding station as the larger one. Fingers crossed!

Also the breeding cone is the only thing in the tank besides a large cube sponge over my canister pick up. I have not removed it as it seems to be the home ground. The fry congregate on it and travel across to mum or dad, an inch or two away, then travel back after a feed. Is it best to remove it? I'm concerned with the conflict it may upset them to much if its taken away as they are happy to keep it between us and the kids when we are around.

The original fry now about two and a half weeks old and starting to look like little fish, filling out in shape a bit now. I notice the growth more now each day with them.

A very happy Australia Day to you all! Time for a beer!

Cheers

[Hooked]

Hi,
everything settled down after their dust up. They seem to be sharing more in the carers roll now. So far so good. There's about 70 odd at this time. Still to hard to count. The remaining six from the first batch still in there too. There's usually a few groups of the babies around the tank and the parents gather them all up from time to time in passing. They are now feeding on micro worm as well as the parents. The micro worm seem to stay in suspension well. I tried the bought bottle of hatched baby brine shrimp but they are not interested. They will have some live brine shrimp to try tomorrow. The three week mark seemed when this lot started to eat from other than the parents.
Finally a clearer pic with about half the fry visible. You can see one of the older fry to the right of the pic. It shows the difference a week makes between these two lots of fry.

Cheers

[Nev]

I wouldn't stress too much about the young feeding, just get the frozen bbs, they love it, and feed the parents as usual. Get some beetheart from the lfs, the bad stuff that disintegrats as the're eating, the fry love it!

[iro11a]

Fantastic job mate. I agree with nev mine feed on the frooze BBS at the 2 week mark.Just hope the flukes dont get you like its done to me even though i treated the parents but obviously the prazi treatment was'nt in the tank long enough.Check around week 6 as soon as you notice any getting dark or swimming wierd they will have flukes.

Jon

[Hooked]

Hi Nev, Jon,

I've looked here for the frozen bbs. I cant find it? I'd seen you guys recommend it to others recently, I think to Mrs D and have been looking since then. I also found it hard to get the eggs too, but have some now and have live baby brine as of today hatching out. Phew! They love it! : )

The parents hardly eat. Any usual type food goes in and gets sucked back out later. I've had to use black worm as its live and doesn't pollute, which can be left in. But they hardly seem to touch them unless they crawl right under their noses? I guess they have their minds on the job at hand.

Thanks also for the flukes tip. I'd noticed you talking about that recently too and was concerned. I asked a few questions (Thanks Illusn for info!) to try and be ready and can use the Potassium Permanganate after about 3 weeks age at the recommended dose in the sticky. I think that would be the gentlest method at this small size IF I have any turn up. It's good to know what specific signs to look out for now though, thanks.

They are doing a great job.... I'm just the cleaner! : )

Thanks for all the good info you are putting out there,

Cheers

[iro11a]

Flukes are the biggest hate for me. I have prazi all tanks and to be certain i have repeated the does after a few days so treating 3 times in a week to break the cycle so far so good for my adaults but loosing a few fry but i think the damage had already been done before i started treatment, going well now after treating them.

I just hope your parents was clean of gill flukes before they laid because i treated mine before breeding but they must have still had some so now i'm at the stage of treating them again but doing more treatments to break the egg cycle, fingers crossed for next spawn.

Looks like your fry are progressing really well if i was in perth i would be grabing some juvies of you for sure :D

Jon

[Hooked]

Thanks Jon,

They laid within 3 days of arriving so I didn't get a chance to treat. They (parents) are not showing any signs but that doesn't really mean anything. I'm ready to go with a PP treatment and am watching for them like a hawk. It was your recent posts about your fry that alerted me to the threat so a big thanks for that.
I hope your fry settle and the next spawn is free of the flukes.
I may be sending some young ones back to Sonle the Melbourne supplier, depending on how many survive, ratio of potential Pidgeons to spotted Butterflies etc that I'm told may arise, "how many I can bare to part with" : ) He will then have for sale and he's an excellent shipper. I reckon there's some good genes in this pair. He's had some excellent stocks coming in recently. He doesn't advertise much, I guess he doesn't have to.

Cheers

[iro11a]

You got a fantastic looking pair mate, i found the pp treatment did more harm to the fry then prazi on a little test i done but everyone has different methods that they think work better but i have had better results with prazi for flukes.I might be chasing either another pair or some females as i have too many males :D

[Hooked]

Hi Jon,
I didn't realise that about PP on fry. I'll definitely look into it. Do you recall what strength solution you used of the PP? Perhaps also the brand of meds. Also would you know Jon what is the minimum age/size fry we can use Prazi on?
I appreciate the info mate.

Hah, I've got to many females! : ) I've got a really nice Albino Red Spotted Green female. Bought some more ARSG's to hopefully pair it up but I think still all females...
Oh well, all in good time,

Cheers, Nigel

[Wendy]

Hooked you can usually get frozen BBS from Aquotix but they are out of stock atm....they do have some on order. Also I got some BBS eggs from them last week and the hatch rate is excellent. The previous ones I had (from another supplier) were pretty much useless.

[iro11a]

I did the treatment of prazi around 6 weeks old i wouldt treat before then.When i did the prazi treatment i lost a few but not as many as i did with the 2mg/l dose of the PP but i suppose different results for different people.

Jon

[Hooked]

Hi Wendy,

Thanks. They told me they were out also. Vebas were also out, but they had a good supply of eggs. Hatch rate has been very good also thankfully. The fry are loving them,

Cheers

Hi Jon,

Thanks mate, food for thought. Fingers crossed I don't get a batch of Flukes go through the fry,

Cheers

[Hooked]

Hi gang,
I've not been around much lately. Relocated etc and just getting back into breeding. I thought I'd just add to this thread something that I realise now I was doing wrong.
I was using canister filters on the set up in this thread and to stop the fry being sucked up I had the pick up pipes covered with large rectangular sponges, about 100mm x 100mm x 300mm. I thought I was doing the right thing by reducing the suction. This worked great to stop sucking up the fry but I created a very large surface area for good and bad bacteria to grow on. They were possibly not squeezed in a bucket as much as they should have been to clean them. I had the fry every now and then showing signs of distress, inactivity etc and thought it was the dreaded fluke. I used Potasium Permangenate to treat them but in the end found it could be harsh on them.
I put it down now to bacterial infection from the large sponges as using another anti bacterial agent was what seemed to bring them right until the bacteria present in the filters took hold of them again.
The tried and true method of a smallish sponge filter with large water changes and a squeeze of the sponge to remove bacteria, crud etc, vac after each feed, is obviously the way to go.
I have wrigglers again now and I'd be keen to hear from anyone if they have had any luck using cannister filtration with raising fry. My main reason or train of thought for using them is that I'm busy most days till late afternoon/evening. I have someone feed my fish three times a day, but they aren't able to vac up after the feed and top up the water. I'm trying to ensure the water is kept as clean as possible with the filtration. Then I'm hoping to be doing regular vacs in the evening with a large water change and frequent cleans of the filter media as I realise this is an area harmful bacteria can grow...... Thoughts?
Also, is anyone using zeolite or any other form of nitrate remover with any success when unable to do the frequently required water changes due to work/time constraints? I ask this as I'm sure I saw a post a while back where someone put up a pic of there set up and it was like a large round plastic open container a bit like a sump and I'm sure it had some form of volcanic rock in it? I think it was a grow out set up? I'll have to search for it again.
All thoughts and experiences appreciated,

Cheers

[sdiscus]

Frequent water changes are also not for me.... I am currently breeding a Blue Diamond pair. I have put a few plants to keep nitrite low. Last time I changed water around 5% a month ago, which will be be probably discourage by most breeders. I flush the breeding tank with PP and this is where I do water changes, but not too much. I also pump water through a 1 or 5 micron filter a fortnight or so just to get rid of any free swimming bugs, but only when there is no fry in the tank.

The practice of not changing water too much I learned from a breeder in Central Cost. He had four breeding pairs and claimed that he did not change water very often... probably a bucket a week which equals 1%. I bought some nice fish off him.

[Hooked]

Hi,

Thanks for taking the time to post your experiences. I'm not breeding at the moment. I'm to busy. Ive put in a large rain water tank recently and will go back to breeding with regular changes in the future. The cost of electricity is putting me off a bit also at the moment. We're looking at fitting solar panels which will make me feel a lot better about running all the equipement involved in the hobby re extra tanks, heaters etc. My display is approx 1000lts and gets a 75% wc once a week with aged/heated water. The fish are happy and always exhibiting breeding behaviour, especially after the change. I find the more I'm in the hobby the easier it becomes of course as you develop quicker and easier ways of water changing, holding/aging water, pumping etc. I get a lot of satisfaction out of keeping Discus.
I wish you well with your breeding pair mate. It's very satisfyng watching them grow.

Cheers



Frequent water changes are also not for me.... I am currently breeding a Blue Diamond pair. I have put a few plants to keep nitrite low. Last time I changed water around 5% a month ago, which will be be probably discourage by most breeders. I flush the breeding tank with PP and this is where I do water changes, but not too much. I also pump water through a 1 or 5 micron filter a fortnight or so just to get rid of any free swimming bugs, but only when there is no fry in the tank.

The practice of not changing water too much I learned from a breeder in Central Cost. He had four breeding pairs and claimed that he did not change water very often... probably a bucket a week which equals 1%. I bought some nice fish off him.

[sdiscus]

My setup is similar to yours... my display tank is around 800+ liters. The full tank volume might be around 900-1000L with the sump...My adult discus keep breeding in the display tank which I am not fond about as they become too aggressive and territorial. In addition, there is no chance of fry growing up in a community tank... I laugh at this when I hear stories about that. That is why I have removed my blue diamond pair. The other ones are still keep trying to raise fry...

I concur with you re electricity cost.. That is why I have installed solar panels. Also, I have insulated the back side of the display tank and the sump. This helps a lot in savings since the amber temperature could be around 14C sometimes.

Be careful with rain water as it might /will have parasites if not properly filtered. I have found it from my own experience.
...
At the moment, I am still fighting fluke...The fry keeps dying ... which is really frustrating..this bug can survive anything..
I can only knock it back a little bit with PP or fluke tabs..but it comes back...
I do not believe that gentle thing like Prazi or Kusuri Wormer Plus (Flubendazole) do anything to the fluke.. It is waste of time and money in my opinion. I have tried all that.

Discus are fascinating fish...But happy Discus are even more fascinating...

[Hollowman]

Happy discus like clean water, anything else is like russian roulette. Advocating NOT changing water is bad for new keepers to read. I will never promote bad practice. It just doesn't work and breeds unhealthy stunted fish.