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Mixing Hardwater Species in a Community Breeding Tank

5K views 14 replies 5 participants last post by  okiemavis 
#1 ·
The Catfish Tank of Sex has done so well (heck, it's got Bristlenoses, Cories, and now even Angelfish laying eggs) that I am considering a second 55 gallon community tank with an eye towards some more fecund fishies, this time in a hard water situation.

So, my question to you is, would it be wise/possible to do a dozen sailfin Mollies (2 male, 10 female), and a half dozen Julidochromis sp. (probably transcriptus, but I might could find myself with one of the others) in the same tank with good Tanganyika style water?

I have a friend who breeds and raises black sailfins in 100% freshwater, so I am not worried about salt (it's not necessary for Mollies so long as they can osmoregulate with calcium ions), so those would be available, and I am pretty sure I can pick up some Julies without too much difficulty.

If the idea isn't a complete bust at the outset, what I would do is set up a 55 with rockpiles each side and slightly off center built around half flower pots, all sitting on black sand, and plant the sand with vals and hornwort, also adding some java moss to better conceal the flowerpots, and maybe some java fern to make the top of the rockpiles more cheery. Filters would be two good sized internal filters, one at each end.

What do you figure? Feasible? Attractive?
 
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#2 ·
tophat665 said:
The Catfish Tank of Sex has done so well (heck, it's got Bristlenoses, Cories, and now even Angelfish laying eggs) that I am considering a second 55 gallon community tank with an eye towards some more fecund fishies, this time in a hard water situation.

So, my question to you is, would it be wise/possible to do a dozen sailfin Mollies (2 male, 10 female), and a half dozen Julidochromis sp. (probably transcriptus, but I might could find myself with one of the others) in the same tank with good Tanganyika style water?

I have a friend who breeds and raises black sailfins in 100% freshwater, so I am not worried about salt (it's not necessary for Mollies so long as they can osmoregulate with calcium ions), so those would be available, and I am pretty sure I can pick up some Julies without too much difficulty.

If the idea isn't a complete bust at the outset, what I would do is set up a 55 with rockpiles each side and slightly off center built around half flower pots, all sitting on black sand, and plant the sand with vals and hornwort, also adding some java moss to better conceal the flowerpots, and maybe some java fern to make the top of the rockpiles more cheery. Filters would be two good sized internal filters, one at each end.

What do you figure? Feasible? Attractive?
If you mix the julies with the mollys you're going to have a lot of dead mollys, and probably pretty quick. While the julies don't get real large, that says nothing for their aggression level, and during spawning, even more so.
If you want something that would work with the julies, try any of the larger rainbow fishes... bosemani, precox, etc. Don't crowd them, either... so not a lot of fish, lots of plants and rock work. The rainbows will be mostly mid to upper dwelling, while the julies will mostly stay down to the lower level... add the speed of the rainbows, and they should be pretty safe.

If you decide to go with the mollys, I could think of a lot of other fish compatible, but raising fry will be dependent on what other fish are there (so they aren't eaten immediately at birth) and how well decorated the tank is. 10 females to 2 males will probably cause some of your females to turn male. Count 2 -3 females for each male and you should be good. Mollys are dimorphic like clownfish, so if the population dictates more males are needed, the females will change sex, and that can happen at any age once mature. I have seen it happen as quick as 16 wks of age.
 
#3 ·
Well, since the point is to produce fry to feed a pack of hungry bushfish, I think the Julis have got to go for now anyway. I have a 20 long I might could use for a breeding pair of Julis when I get to that.

Dawn, if you like, I'd love to hear your ideas on suitable molly mixers. My vision is to have the mollies be the only fish in the mid and top water, and I want to keep a goodly number of fry, so seriously skilled fry eaters (another strike against the julis, I bet) are out. If the other fish were to breed too, so much the better. Some sort of limia, maybe?

Or work a bit closer to neutral and go with a shoal of Cories. Looks like C. metae does well in medium hard, slightly alkaline water.
 
#5 ·
I have three kinds of vals, plenty of java moss, two types of java fern, and I'll get hornwort for bushy cover and anachris for snacking. If I am not going to have diggers in the tank, then I have dwarf sag aplenty to carpet with. I far and away prefer to keep plants in tanks. One reason why it's unlikely that I'll ever get into Mbuna.
 
#6 ·
tophat665 said:
Well, since the point is to produce fry to feed a pack of hungry bushfish, I think the Julis have got to go for now anyway. I have a 20 long I might could use for a breeding pair of Julis when I get to that.

Dawn, if you like, I'd love to hear your ideas on suitable molly mixers. My vision is to have the mollies be the only fish in the mid and top water, and I want to keep a goodly number of fry, so seriously skilled fry eaters (another strike against the julis, I bet) are out. If the other fish were to breed too, so much the better. Some sort of limia, maybe?

Or work a bit closer to neutral and go with a shoal of Cories. Looks like C. metae does well in medium hard, slightly alkaline water.
If you want to produce molly fry for feeding other fish, put your adult mollys into a tank of their own and scoop out fry as you need them. Anything like julies will chew up the adults, not for food, just for the sake of tearing them up.

As for other mixes with the mollys... if this is to be a 55 gallon tank, you actually have a lot of options, and if it's as well planted as you're describing, you could probably pull off quite a lot.

If you want mollys as your primary mid dwelling fish, maybe try some of the small blue eyed rainbows? Furcata can get a little nippy, but with that amount of plant cover up top, I would think that could work easily enough, or signifer, which aren't as nippy. Those would be my first choices for upper dwelling to create what you're describing. Hatchet fish could also work, but stick with silvers as they're less agressive than marbles and can handle a wider range in hardness.

For bottom dwelling, you could work with corys, but there are other options. Depending on how hard you're planning to keep this tank... there are a number of botia loaches that could make for a nice school down below, active and pretty.
You could also add thai flying foxes, but be sure they're the true flying foxes, the ones that feed on hair algaes... they won't hurt your plants and will school nicely if you provide them a group of at least 5 - 7.

And don't forget inverts!!! You can get a lot of variety with inverts instead of fish, less waste production, and they'll help maintain the tank for you. Ammano shrimp, ghost shrimp (don't mix shrimp species, the largest species will eat the smaller ones)... avoid whisker shrimp which eat fish and get quite large. You could add bamboo shrimp, which are filter feeding and compatible with ammano shrimp... most of the shrimp can be slowly acclimated to harder water and still thrive just fine... and again that will depend on how hard it is.
Let me give this some more thought, I'm sure I'll come up with more ideas if I really sit and think about if for a little while. It has been a long and busy day/night on this end and those are the things just jumping off the top of my head that are obvious mixtures to me.

Hope this helps!
 
#7 ·
Dawn - Fry for feeding are the primary goal, but at the same time, this tank will be in my living room, so appearances are important. A large group of black mollies (or wild type latipinnas) in the midwater would make a pretty stunning display by themselves, but I would like to add some point of interest to the bottom strata as well, and, if that fish were also a good breeder, so much the better.

TFH had an article a couple of monthss ago in their livebearer's corner about setting up an all Livebearer community, so one of the ideas I have is to add limias, as I understand they stick closer to the substrate.

Another is to add cories and divide the substrate up into zones of sand and large pebbles that cory fry could get down between to grow out a bit.

Yet another is to discard the idea of a second breeding species entirely, make the tank lightly brackish (<1.005) and add a 1 or 2 violet gobies. I understand that they can get 20" long, but it is my understanding that this rarely happens, and they usually top out between 12 and 18".

For fry production purposes, cichlids are right out, I expect, as they would very likely eat the molly fry, and it seems to me that most cichlids that would breed in hard water would also be tough on plants.

Regardless of what else goes in there, I'm thinking that throwing about 20 ghost shrimp in might be a worthwhile endeavor, since they might well breed. I would start with just 10 and keep an eye out for any long claws that might have slipped in.

Another thought: Florida blue-fin killifish. These guys come in with ghost shrimp shipments pretty frequently, and my LFS sells them as "darters" for a buck.

Darters... Now there's an idea. That would take some considerable research that may ultimately prove fruitless, but aren't there several species of southwestern US, northern Mexican darters that might do well in a tank with mollies? Or would the current need to be too strong?
 
#8 ·
tophat665 said:
Dawn - Fry for feeding are the primary goal, but at the same time, this tank will be in my living room, so appearances are important. A large group of black mollies (or wild type latipinnas) in the midwater would make a pretty stunning display by themselves, but I would like to add some point of interest to the bottom strata as well, and, if that fish were also a good breeder, so much the better.

TFH had an article a couple of monthss ago in their livebearer's corner about setting up an all Livebearer community, so one of the ideas I have is to add limias, as I understand they stick closer to the substrate.

That could work, but you may find that with mollys in the tank, they may tend to spend a lot more time in mid to upper levels of the tank with the mollys. Also being live bearing, watch your male/female ratios... as much as you want the fry for feeders, you also don't want to be over run with so many that you have water quality problems. My 90 gallon was devoted to breeding mollys, and I started with 6 females and 2 males. Lo and behold, one of my females even turned male on me, and it only took 3 months to end up with over 200 fry in that tank, and needing to do daily water changes to keep up with waste levels. I was not using the fry as feeders, but about 50 fry/month were going to the store to trade for plants. If using them as feeders, 50 fry is a lot of fish for a month... and in a 55 gallon, you're stocking limits will be less than mine were. When you count your female/male ratios, be sure to include ALL livebearing fish in the tank and expect 30 - 50 fry every month from each female, if not more. They are each capable of having up to 100+ each month, and in retaining sperm from mating for at least 3 - 4 spawns. Also remember that any livebearing female you bring home from a store is likely to already be pregnant, and could have 3 - 4 spawns before every having a male in your tank. You might want to consider starting with females alone, and add your males later...


Another is to add cories and divide the substrate up into zones of sand and large pebbles that cory fry could get down between to grow out a bit.

I would not suggest the sand. Corys can do just fine in small to medium size gravel. Sand and gravel will bleed together and mix, sand will circulate in the water whenever disturbed, which can lead to filter problems, and sand is very difficult to clean waste out of. Many years ago I listened to someone who suggested that to me, and I learned the hard way it doesn't work. Sand also will not benefit your biological filtration, it's too dense for the bacteria to culture in normally, and sand is too dense for most plants to grow in very well. Anythng with a root structure is a no no in a sand substrate long term. I have raised crypts in sand, but it was very difficult and they didn't grow as well as in gravels.

Yet another is to discard the idea of a second breeding species entirely, make the tank lightly brackish (<1.005) and add a 1 or 2 violet gobies. I understand that they can get 20" long, but it is my understanding that this rarely happens, and they usually top out between 12 and 18".

I would skip the violet gobys. Size is one issue, of course. The reason most don't grow to full size in a smaller tank is the same reason any other fish won't grow... growth gets stunted due to water quality issues and you end up with internal problems and damage. Size restrictions like that in an aquarium will also cause physical deformities. Another issue is that the violet gobys will also feed on your other fish, and if it fits into the mouth, it's fair game. This is not conducive with keeping fry or anything smaller than will fit into the mouth of the goby. Overall, bad idea with this one.

For fry production purposes, cichlids are right out, I expect, as they would very likely eat the molly fry, and it seems to me that most cichlids that would breed in hard water would also be tough on plants.

Correct. Cichlids will chew up adult mollys, which means no fry to eat. As for plants, if the cichlids are African, then expect plants to be eaten. If they are Central or South American, most will need softer water and they still tend to do a large amount of digging, which can make keeping a planted tank a challenge. Dwarfs would be the only cichlids to do really well in a planted tank, and again, you're looking at pretty soft water.

Regardless of what else goes in there, I'm thinking that throwing about 20 ghost shrimp in might be a worthwhile endeavor, since they might well breed. I would start with just 10 and keep an eye out for any long claws that might have slipped in.

That sounds like a good idea. With enough plant cover, ghost shrimp tend to breed pretty easily. Expect it to take a few months before you see anything for fry, though. It takes a while for ghosties to settle into their environment, and you'll want to make sure you have at least 2-3 males out of the 10 to ensure breeding success.

Another thought: Florida blue-fin killifish. These guys come in with ghost shrimp shipments pretty frequently, and my LFS sells them as "darters" for a buck.

Now that could work... but watch the fry population... they will still feed on some of the smallest of fry unless they're very well fed... and that means a lot of water changes.

Darters... Now there's an idea. That would take some considerable research that may ultimately prove fruitless, but aren't there several species of southwestern US, northern Mexican darters that might do well in a tank with mollies? Or would the current need to be too strong?

I would rule out darters alongside of the violet gobys. Again you are looking at something with habitat requirements that will differ greatly from the mollys, and you're also looking at something that no matter how small when you get it, will eat your fry. Daters tend to have very healty appetites when there is plenty of live food around to amuse themselves with. I wouldn't mix them for the situation you're trying to create.
If you go brackish, there are a few options for you there... but you'd want to provide a lot of rocks down low with plenty of holes to hide in... what about bumble bee gobys? While they might eat some fry, a school of 5 - 6 of the bumble bees shouldn't do too much collateral damage there, they're pretty, and fun to watch. They "hop" around on rocks, stick to the bottom 1/3 of the tank, and actually prefer live black worms and brine shrimp over fish fry for food. That would satisfy your desire for a goby and also for something that stays on the lower part of the tank, and is harmless. If your ghost shrimp have enough places to hide and you start them as adults, the gobys shouldn't bother them. If you can get enough decorations in there, I see no reason why your ghosties couldn't successfully breed in there, either.

As for upper level in brackish water, I'd have to give that one a lot more thought. Most things I am thinking of at the moment are not going to work with a molly tank where fry are desired. But, if you don't mind another mid to upper level fish, orange chormides or indian glass fish can be quite awesome, and very compatible with the mollys. The brackish water will also ensure better success with your molly breeding, and your adults will be stronger and healthier than if in fresh water.
If working with brackish water, you could then use crushed coral as a substrate, or mixed with a medium grade of gravel for a substrate... and there ARE a number of live plants that would grow well in a brackish tank if you could accomidate the acclimation process which takes a few months of gradually increasing salinity. This would easily be done if you started with just mollys, added the specific plants (needle sag, anubias, crypts, java fern, and a few others) and then slowly bring up your salinity over the course of a few months. If you increase it very slightly each week, by about 1 tbsp... until you get the proper salinity for the other fish, you could create something very unique, awesome, and great to watch! (and functional, too)
 
#9 ·
Right then. Mollies, Ghost Shrimp, and limias if I can find them, maybe just a few blue finned killies (I'll do a little research on those first.)

Now, about the sand, I have never had any luck getting any grasslike plant (Vals, Sags, Hairgrass, or Chain Sword) to grow in anything But sand or Eco Complete. On the other hand, I have managed to get some nice lawn action from Dwarf Sags in play sand eco complete, and Tahitian moon sand, and My vals are thriving in Moon sand too. So, I think I am going to have to go with the sand there, but I am going to do three things to keep it from getting out of hand:
1) Rockwork: Lots and lots of yellowish white feldspar in the streams around here. If I can find the right pieces, I'll go iwagumi with it. I not, well, Walls and terraces are nice. Probably put some flexible plastic sheeting behind it to retain the sand behind it.
2) Heavy planting - vals back and side, dwarf sags in the front, crypts between.
3) Malaysian trumpet snails. Keep the gravel stirred up.

My thoughts on the stock levels:
I expect to go through an awful lot of fry. I currently have 3 Leopard Ctenos about 3 1/2" each, and They'll be going into a 110 by June. I'm going to add another 3 Ctenos to that, and a pair of Senegal Bichirs. I think they can handle 200 baby mollies a month, and I can vary the food I gutload the fry with to vary their diet. Let me be clear that I don't intend to feed fry exclusively, but I think they would make a good staple.

To round that out, I'll pull the most promising fry into a grow out tank (Probably a 30 gallon plastic tub) and feed them up to auction them off or trade to the fish store for coupons.

I'm not concerned about sex changing fish. so long as I have enough females to keep the males from pestering them to death.
 
#14 ·
iamntbatman said:
Don't want to change the topic completely...but are you completely settled on hard water and mollies? If not, a 55 full of convicts could provide a damn good fry factory for feeding your bushfish.
It's not so much that I am settled on the Mollies as 1) Convicts and Plants aren't as good a mix and I do like a planted tank and 2) I have a friend who breeds really high grade black mollies who I could surely buy a dozen or so from.
 
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