Stocking questions   12/7/10
In a compromise with my wonderful wife, I have just got a new 125 gallon aquarium with two emperor 400 filters and an undergravel filter.
<Cool.>
As part of the deal I needed to downsize the number of aquariums to the 125 and an established 65 gallon aquarium.
<Fair enough.>
I am seeking advice on stocking these tanks with fish I currently have and/or any new additions that would be compatible.
<Okay.>
My 65 gallon currently has 6 Electric Blue Jack Dempseys all about 3 to 3.5 inches.
<While the "Electric Blue" morph (or hybrid?) variety of Rocio octofasciata is somewhat less aggressive than the standard sort, they're still very aggressive fish. A mated pair could easily cause problems in this aquarium.
Do read my piece on these fish over at Tropical Fish Finder, here:
http://www.tropicalfishfinder.co.uk/news_article.asp?id=2055
As you presumably realise, breeding in captivity is very uncommon, which is why some suspect they're a hybrid rather than a true variety.>
Two Pictus Catfish about 5 inches each and 2 Royal Plecos about 4.5 inches each.
<Pimelodus pictus is a schooling species, and should really be kept in groups of 5+ for consistently good results. By contrast, Panaque nigrolineatus is highly territorial, and there are reliable stories of males killing one another as well as females. While these are by far my favourite of the Loricariidae -- my own specimen is about 16 years old now -- they are normally kept one to a tank, and not alongside any other Loricariid of similar size or shape (they ignore very different Loricariids such as whiptails and Otocinclus).>
I was planning on slowing moving these fish to the new 125 gallon.
<Okay, but I still wouldn't expect two P. nigrolineatus to coexist in this tank. Be aware of the risk of problems, and look out for signs of fin damage as an early warning that your specimens are fighting. Serious fighting involves the stronger fish literally flaying alive the weaker one using its very powerful teeth.>
Understanding that these guys are still growing will this be an suitable set up?
<See above.>
If more fish could be added, would Tiger Barbs be a suitable addition or what would you suggest?
<Tiger Barbs wouldn't be my first choice for use alongside any cichlids, given their nippiness. Giant Danios, Spanner Barbs, Clown Barbs, Nurse Tetras, or Mexican Tetras would all strike me as better companions for medium-sized cichlids.>
In the 65 gallon I would like to keep a Black Ghost Knife Fish. I have read that they can get big and if it got to say 12 inches would the 65 gallon be a suitable home for it?
<Barely do-able. Apteronotus albifrons is a sensitive species, and the vast majority die prematurely. Ask yourself how many adults you've ever seen at their full 50 cm/20 inch length? Or living for 10+ years, as should be the case. Outside of public aquaria, it's rare to see them so large or so old.
Why? Because they need quite specific living conditions that mimic the cool to middling temperature, oxygen-rich, brisk water currents found around riffles and rapids in rainforest streams. So while it's true that A. albifrons tends to stay fairly small in home aquaria, that's perhaps more a reflection on the fact they die within a couple of years rather than any sort of "growing to the size of the tank" malarkey. Take some time to think about their needs, establish how you're going to provide the right level of water turnover -- 8-10 times the volume of the tank in turnover per hour -- and also check to make sure you can provide the soft to moderately hard, slightly acidic to neutral, nitrate-free water chemistry essential for long-term success. There are other species of Knifefish with easier requirements, perhaps most notably Xenomystus nigri, a non-electric species from a completely different family of fish able to breathe air and naturally found in sluggish rivers. It's smaller too, 30 cm/12 inches being the absolute tops in terms of size, and most getting to rather less. By the standards of its family, the Notopteridae, it's fairly peaceful and can be combined with a variety of robust tankmates.>
What are good tankmates for a Black Ghost Knife?
<Essentially species that come from similar habitats, with the provisos that very small fish (such as Mountain Minnows) may be eaten while competitive bottom feeders (such as loaches and catfish) will make it difficult for you to keep your Apteronotus properly fed. All things considered, they are best kept alone, or with a largely herbivorous catfish species such as Ancistrus dolichopterus. Open water schooling fish might be chosen, for example Bleeding Heart Tetras, Silver Hatchetfish, Demasoni Barbs, Swordtails or Australian Rainbowfish, depending on your water chemistry.>
Thank you for sharing your knowledge and time.
<Glad to help. Cheers, Neale.>
Re: Stocking questions  12/10/10
Thank you for the great information. I will separate the two Royal Plecos as soon as my 125 gallon has safely cycled. They are both incredible fish and do not want them to hurt each other. I will also add some additional Pictus Catfish. If I may ask a few more questions about the Electric Blue Jack Dempseys? Will a 6 foot 125 gallon tank be enough aquarium for Royal Pleco and Pictus to thrive and also allow the Jack Dempseys to set up their territories. These fish are all young and will grow older together, will this lessen aggression from the Jack Dempseys? So far there have been no aggression issues but the Jack Dempseys are all of equal size or smaller then the other fish. Once again thank you for your help and merry Christmas to you and yours.
<Jack Dempseys aren't really community fish, and while they could coexist with a larger Panaque nigriventris, given sufficient hiding places, I would not mix them Pimelodus pictus. As I hope you realise, Pimelodus pictus are quite peaceful schooling fish and they're easily harassed by aggressive cichlids as well as nippy tankmates. Good companions are things like Silver Dollars, Australian Rainbowfish, Severums, and so on. They also prefer soft water, whereas JDs need hard, alkaline water. Now, Electric Blue Jack
Dempseys add a further level of complexity to the situation. While they do seem to be marginally less aggressive than regular JDs, this may be because they're rather inbred animals with poor quality genes. One of the things that people have observed with EBJDs is their delicacy. They just aren't hardy fish and whatever inbreeding was required to create them, thanks to their popularity, they're getting worse as people breed them to a price rather than a quality. Personally, I wouldn't touch them with a bargepole,
but if you do want to keep them, at least make an effort to get good quality stock, rear them in their own environment away from other fish, and ensure water chemistry, water temperature and water quality (including nitrate) are ideal for the species. There are much better blue cichlids you might keep, for example Blue Acara, these latter getting along perfectly well with Pimelodus and Panaque species. Perhaps not so garish in their shade of blue, but far more elegant and natural. Cheers, Neale.>

Jack Dempsey not a jewel cichlid:( Cichlid sel...  2/9/08 I am so upset. Yesterday I went to my LFS and I wanted a jewel cichlid. Not knowing they gave me a jack Dempsey instead. Now here is the problem. I have a 40 gallon tank and it is too small for a jack Dempsey. <Indeed.> I do like the fish but I know it is too small for it. I tried returning it but they said I wasn't allowed because they were afraid it might have a disease and infect their tanks. <Certainly they are at liberty to take this attitude.> So do you think it will be fine to leave it in a 40 gallon tank or no. <Are we talking those paltry little US gallons or the nice big and beefy Imperial gallons? 40 Imperial gallons is about 48 US gallons, and that would be fine for a single adult JD. But forget about tankmates! 40 US gallons is a mere 33 Imperial gallons and too small for an adult JD. A juvenile would be fine for a while, but once it tops about 5", it'll need rehoming.> I will keep up with the water changes every week. What do you think? Thank you so much for your response. <Please do remember our mantra -- read about a fish before buying it. There is no way anyone who has seen a picture of either a Jewel Cichlid or a JD could confuse them: one is bright red, the other steely blue. It's hard for me to grasp how the store could trick you here if you had actually read anything about these fish, and moreover if you couldn't tell they were hoodwinking you, you probably weren't adequately informed to be keeping them anyway. So do look for a nice cichlid book, sit down, have a read, and then enjoy what is actually a very pretty, if aggressive, Central American cichlid. Do note that this species has entirely different water chemistry needs to a Jewel, and set up its quarters accordingly. http://www.wetwebmedia.com/FWSubWebIndex/dempseyfaqs.htm Hope this helps, Neale.>