adding new discus to an established tank

[oliverk]

Thinking/would like to add new discus to my established discus tank. The current tank is as follows, 120 gallon planted with an aquaponic based filter that has another 25 gallons of water and another 40+ gallons of filter media supporting the plants (veggies and what not) and which water flows through and over. There are 9 discus grown out from 2.5-3 inch to their current 5-6.5" inch sizes. Also there are several panda corys which vary in number due to breeding and being eaten. I am pretty sure I can easily support 4-6 more discus at full size in this tank and do not object to, indeed would prefer to watch them grow out.

I've read many yes's and many do not and several why take the risk on mixing asain and german strains. I have a couple of LFS that stock Asians and I bought germans.

I've received advice and saw at discusfish.com and was not able to find anything here that if there is too much size differential between new and old fish that there could be problems of aggression and stunting... Discusfish.com mentioned that the larger fish may even excrete a hormone that will stunt the new smaller fish's growth. Seems like the 4-4.5 inch size would be an ideal introductory size - good for the 2.5 and good for the 5-6 and indeed that is consistent with advice and discusfish.com's published information.

My wife and I very much enjoyed watching the current set of discus grow and change over time, so in addition to price considerations our inclination is to smaller quality fish from a reputable source.

In addition to moving decorations and etc. I have also read that it is generally better to introduce more than one fish at a time to create a new pecking order/territories etc in the tank.

While I do have a very lightly stocked 20 gallon tank identified as a quarantine tank it (Planted with 4 3" feather fin orange and black tetras bought at LFS and 2 3" corys also from LFS) it a) has different type of filtration water changes and slightly different replacement water chemistry and b) limited capacity to support fish. There is no way to practically get and set up a new different or larger quarantine tank.

Mail order fish work to some extent work best if bought several at a time. The last mail order germans took several hours to recover from their travels and worry about lethargic fish in the main tank with the existing nine while recovering from travel... Later there might be enough cover with the plants and "roots" to give smaller discus enough cover.

So had been thinking of solving the 4-6 week quarantine issue by introducing into the main tank at the same time starting a Paraguard treatment for 7 days and continue/augment as needed. This leaves a bunch of questions of course... might be able to have a short term transitional holding area for flight recovery, but heating in a plastic bucket has issues.

Buying from local fish store has issues of Asian/Euro disease resistance and general quality concerns. Mail order should really be more and perhaps smaller fish but runs into too large a size gap issues.

So thought I'd pose the problem and see what you all think and why.

[adrian31@outlook.com]

As you know, it's highly recommended to quarantine for 4-6 weeks so I'm sure you'll hear that quite a bit. But it's for a valid reason which, if you forego the process, you may be faced with. I personally know another who knew the risks but took the chance anyway. In this case they lost most of the original tank's group within 10 days but some survived. No problems with the new fish. As I understand they fully realized what could happen but weighed this against the time/effort of quarantine, and were satisfied with the final result.

So my take on this whole thing is that issues happen more than not when mixing Discus from different sources, and quarantine can help mitigate this. But I hear sometimes you get lucky.

[BmoreBraap]

I agree with Kenny...why risk it?
I also was naive to the QT situation because I kept buying my Discus from the same reputable source and did not QT. All went OK for the first few months until I added 2 more straight to the main tank....BAM, massive capillaria infestation that took my months to clear up (and sacrifice 2 fish that had to be sent to a lab for analysis to find out what they had). It sucked, bad. And here you are talking about mixing the strains with 0 QT time.

Personally, I would QT your new fish for the standard 4-6 weeks THEN maybe try adding a hero fish from your Asian line in with the germans and go another few weeks. If everything is still OK after that I'd assume its OK to mix the 2.

[oliverk]

I could possibly quarantine 4-6 2.5"-3" discus in my 20gal "quarantine" tank for 4-6 weeks. The water chemistry differentials between the two tanks are minimal and could be managed as well by using water from the big tank and putting it into the 20gal rather than using fresh RODI plus extra carbon water when doing water changes.... (the big tank gets both RO and RO reject water and the 20gal just clean RODI and final carbon - what we drink water)

Not at all sure I could quarantine multiple 4"-4.5" fish in the 20gal. Just not enough room for them to swim much..... One, sure, maybe two any thoughts.... ? The 20 gal only has a small but oversized back of tank filter on it (rated 30gals)..... Also smaller numbers of larger fish really drives up the cost of shipping per fish and reduces the enjoyment of the grow out on each fish..... and may also bring back pecking order dispute issues as I think the more new fishes and the bigger changes in the tank setup may contribute to a smoother transition.

If, though more expensive, I bought small Germans mail order and used the 20gal quarantine tank this also eliminates any differentials in disease resistance and immediate introduction issues of the new fish being beaten up while recovering from travel and gives the largest period of watching the grow-out.

BIG remaining issue is the size differential between these smaller fish and the ones in the final destination tank........ Really don't want stunted fish or those that are overly brutalized or prevented from growing by hormone secretions......

Any more differing thoughts?

[oliverk]

Alternatively, I could buy 1-2 at a time Asian sourced/bred larger 4"-4.5" fish or 4-6 smaller and quarantine those......

Suspect that the new owners of LFS I'd probably go to (about 18 months since the change) do a pretty good job of getting quality fish and ..... They took over a discus primary store in major metro area and seem to have kept it that way, I think, and is an expansion of their aquarium maintenance service, and seem to have good facebook comments. Much much cheaper per fish but with the larger size involves multiple smaller number of fish introductions and those issues so always worried about new fish introductions over the next year...... and if do the smaller fish have, like with the larger have the persistent issue of differing disease resistance characteristics of Asians and Germans.

[DatDiscusDude]

Once you start to plan, and concoct a solution that seems as in-depth and all over as this to cut corners, you are basically asking for some major headaches...

I'd go straight QT no outside sources, water, nets, hoses etc. Or just add them right in... Going all round about it as you describe above is just a convoluted way to the same results. IMO

[oliverk]

Other than moving a fish from the main tank to the quarantine tank is there anyway to test the resistance of the fish in the main tank to anything the fish in quarantine may have?

I assume I can move water, maybe a plant, some of the media at the bottom of main to expose the new fish to the main tank environment????

Would moving one or two of my panda cory's from the main to the quarantine be enough to test what the main tank can tolerate???? Tough to do of course they move fast etc are small and hide in plants..... (except size same for the discus) and of course stress of move....

[oliverk]

I further gather that the prophylactic treatment just doesn't substitute for quarantine.... sigh

[adrian31@outlook.com]

If I were in your situation I would determine from the seller if all his fish come from the same source. If so, then I would buy a couple and put them, along with one of my current fish (my least favorite), in the 20gal for 4-6 weeks. If all goes well then I'd know there is a decreased risk of mixing the two sources. I would feel more comfortable putting new fish from that source straight into my main tank.

Bear in mind another reason for quarantine is so new fish can acclimate & regain their strength after their journey to reach you, rather than get thrown straight into an already established pecking order which can be brutal on these new fish.

I've added Discus from a reputable supplier straight into my display tank of Discus from a different reputable supplier after checking with both regarding their facilities. I got lucky and my fish were fine other than the new ones having to deal with stress from shipping/being new in the tank. But I understand this is the exception rather than the rule. I've only done this once since I realize any number of factors could change at the Discus supplier each time I buy new fish.

Good luck!

[oliverk]

Once you start to plan, and concoct a solution that seems as in-depth and all over as this to cut corners, you are basically asking for some major headaches...

I'd go straight QT no outside sources, water, nets, hoses etc. Or just add them right in... Going all round about it as you describe above is just a convoluted way to the same results. IMO

??? I don't understand your comment at all...

[mbruizer187]

He's is just stating that you are coming up with all these ideas to try to cut corners on what should be done and asking for trouble. Its simple, Buy new fish from same source, different source, whatever. QT them in their own tank for 4-6 weeks (that means separate water, and instruments, for changing water, cleaning ect. No mixing water from old tank, and putting it in QT. Now after the 4-6 weeks add 1 fish from your old fish to the QT. observe for additional 2-4 weeks. if no ill effects of either new fish or old one, you can try mixing. No wait maybe can I try this or that. Just do it that way. and I have mixed, and did QT and all germans came down with something but all fought through it eventually, some faster than others, healthiest biggest got sickest but fought through. Even hero showed small signs of something not right but didn't slow him down. Then the main tank acted like something was really up. Kept water clean don't let them get bullied and all turned out fine eventually.
Rich

[DatDiscusDude]

He's is just stating that you are coming up with all these ideas to try to cut corners on what should be done and asking for trouble. Its simple, Buy new fish from same source, different source, whatever. QT them in their own tank for 4-6 weeks (that means separate water, and instruments, for changing water, cleaning ect. No mixing water from old tank, and putting it in QT. Now after the 4-6 weeks add 1 fish from your old fish to the QT. observe for additional 2-4 weeks. if no ill effects of either new fish or old one, you can try mixing. No wait maybe can I try this or that. Just do it that way. and I have mixed, and did QT and all germans came down with something but all fought through it eventually, some faster than others, healthiest biggest got sickest but fought through. Even hero showed small signs of something not right but didn't slow him down. Then the main tank acted like something was really up. Kept water clean don't let them get bullied and all turned out fine eventually.
Rich

Thanks Rich... you broke it down better than I guess I did...

I feel like you are trying to come up with a work around OP and that will never work. Either do it the right way and QT as Rich has outlines or just toss the fish in and see. The corner cutting will pretty much get you the same result as no QT at all so why waste the time?

I have gone both ways, have been in your shoes, most here have. Sometimes you win, sometimes you loose... The choice is ultimately yours. I am just saying why do all this mixing and half hearted QT, if you go that route then just chuck the new guys in and keep the water clean and pray.

[oliverk]

The main display tank and the quarantine tank have been completely separate environments for a long time. The thought of moving water and maybe a plant some gravel, and/or maybe some corys to the quarantine, even before the new fish arrive is to more closely recreate the environment in the main display tank.

Again the "quarantine" tank is a 20gal understocked planted tank that gets manual RO changes and uses an hang on the inside canister filter. No water normally is shared by the two aquariums, fish don't go back and forth, I don't move plants or decorations, they have separate tools and I only work on one tank at a time. In most respects it might as well be yours, the LFS tank, or the tank from which I buy mail order fish.

Aren't I a lot farther ahead of the game if I move a bunch of stuff from the main tank to the "quarantine" and get the environments as close to the same as possible for doing the quarantine? Isn't this the reason to use a "sacrifice" or "hero" fish to do the ultimate test? If I do so have I created a bunch of "hero" fish that currently reside in the understocked "quarantine" tank? That would be great!!!! Less stress on both tanks, and relatively cheap easy ($2-$4 ea) replacements in the "quarantine" tank.

Continuing to move water from the display tank, rather than replacing with new clean RO water is to keep the environments as close as possible during the quarantine period and is extra work because of avoiding premature breaking of quarantine issues.

Well hey the retail replacement cost of any 5-6" stendeker discus is $200+ plus shipping which can be as much as $100. If I can use water, plants and a panda cory or three from the display tank to test if the new fish will get sick seems like a better idea and lower risk alternative... if it accomplishes the goal... is a cory(ies) sufficient to test the new discus, or how about the fish currently in the quarantine tank, especially if I move a bunch of water plants and substrate to the "quarantine" or does it have to be a $200+ discus to test?

Additionally, a large discus moved to the quarantine tank will severely limit the number of fish that can be quarantined as I will have to plan for the end of the test loading of the tank...... If I use the pandas or the fish currently in the "quarantine" tank the loading problem is easier.

[mbruizer187]

QT is not just for your old stock, but the new comers first, after travel they are more susceptible to getting ill from whatever your current stock already has. So they get 4-6 weeks to get immune system ready to handle whatever you are throwing at them. Then you can add something to it. Your Qt tank should be completely sterile. Maybe a cycled filter, not from another tank

[oliverk]

Yes the original thought was to even boost the protections, by treating with paraguard a broad spectrum anti parasite, anti bacterial and anti fungal treatment. The label I have even says for introducing new fish to a community tank.

The concern is that sometimes the bad items develop resistance to "treatments" and was wondering if anyone would say something about a) how effective such treatments are on introduction and if they are significantly effective enough to substitute for quarantine??? - the consensus seems to be NO!; ok, B) is it helpful enough in the quarantine tank to be useful? and C) not worth the risk of reducing the efficacy of the treatment ......

I can do this, of course, in the main tank or the community tank, or both.

No one seems to have commented....