Wednesday, December 20, 2006

The Fundamentals of Keeping Mbunas in the Aquarium

By Steven P. Parker

 

Natural Habitat:

Mbuna are a group of mouth-brooding rock dwelling fish that come from the waters of Lake Malawi. Lake Malawi is a rift lake in Africa surrounded by the countries of Mozambique, Tanzania, and Zambia. The lake is also known as Lake Nyasa or Lake Nyssa to the locals who give us the word "mbuna" which loosely translated means tasty “rock fish" in the Tonga Language. These fish live in the crevices of the rocky shores and feed off the algal mats covering the rocks, as well as some of the invertebrates and insects they encounter along the way. Wait, did I say "Tasty?" - Yes, the local tribesman like to eat our prized Mbuna as a delicacy by roasting them on sticks over a small fire! (So maybe it is really "Mmmmm, Buna!”) The locals also eat many other fish we keep in our tanks such as Tilapia, which comprise the largest part of their diets after drying and sun-baking them along the shore. I've had Tilapia Florentine and it is tasty. In fact, Tilapia has been chosen as the food source most suitable for a lunar colony because it contains high amounts of protein and it thrives in crowded tank conditions. Lake Malawi was formed by glaciers in the last great ice age leaving a long deep craggy scar in the Earth. Roughly half of the lakes shoreline is littered with thousands of 1ft-20ft boulders and its depth exceeds 2300feet. The lake is located in an area that is extremely diverse in biotopes and geologically very active, and as a result, the area is known to produce the highest number of species per square mile anywhere on earth! The Rift Lakes and the surrounding area are home to an estimated 1,200 species of Cichlids alone! The mbuna make up about 1/3 to 1/4 of that total. There are over 600 species of Cichlid in Lake Malawi with most being endemic, and over 230 species falling into the Mbuna flock type. Most Mbuna can be found at depths of 3m-10m with about 26 species living at depths of up to 40m! Now that we know a little something about where our fish come from and how they live we can make informed choices on what our wet pets need to be humanely and properly cared for, not to mention providing you something interesting to tell your friends.

Selecting your Fish:

  

There are three stocking methods commonly used to house Mbuna.   They go by various names, I call them;  all-male, hodgepodge, and communal.   I only recommend communal to beginners even though it may be harder to setup initially.   All-male tanks have their place, and hodgepodge tanks are hopelessly troublesome.  

All-Male tanks are fairly straight forward.  You select only males of various species (usually in groups of 5+ at a time)  and overstock the tank to about 1 mbuna for ever 3-4gallons of tank space you have.   You definitely want to try to match the "toughness" of each species and not mix milder species with stronger species.  These tanks require at least double normal filtration and frequent large scale water changes to maintain.  Failing to maintain good water quality tends to cause mbuna to get aggressive with each other so you must be diligent about your maintenance habits.

Hodgepodge tanks are basically the same thing but housing any malawian fish male or female.  They are thrown together in a tank and then you let them fight it out to see who stays and who has to go.  A great example of this type of tank is the "Assorted Africans" tanks we see in many big box stores and many other dealers getting their fish from the fish farms in the south.   These fish are analogous to puppymills churning out a huge supply driving down costs without any concern for genetics.

Communal style housing consists of ideally keeping species in "quads" of 1 male fish and 3 Female fish.  Minimum should be 2 females per male as he can get pretty aggressive with her during mating and having more girls to spread his love to lessens his abuse on any particular one of them.  More females for each male is always better, but after about 8 females the male may not show as much interest in the extras.  A sub-dominant male can sometimes be housed when there are plenty of females to go around.  A sub-dominant male will rarely challenge the dominant male after the initial 24-48hours.  If the two males continue to challenge after that it is best to remove him.  

Tank size:

Your aquarium is the most important part of your success with keeping Mbuna. This means the bigger the better! However, while that is always true, capacity is less important than footprint. The footprint of a tank is determined by measuring its Length in Inches and multiplying by its width in inches. (L x W = footprint) On average, Mbuna males need about 200 square inches of territory. Some species require a lot more and some require a bit less, but 200in.² is a good starting point. This means you want to maximize your capacity in gallons to your footprint. Don't worry, I have done the math for you on all the standard sizes already! This table will tell you what you can do if you choose species wisely. Generally I do not endorse trying to have more than one species in any tank smaller than a 4ft tank preferably a 55g. Distance between males also plays a role, as will aquascaping, so this is only a guide based on the rest of my suggestions elsewhere.

Tank Size	Base (in.2)	Notes
10 gallon	200	Should not be used for anything more than a hospital tank.
20 gallon HIGH	288	Poor choice, see above.
20 gallon LONG	360	Highly restricted species selection.
25 gallon	288	Another poor choice.
29 gallon	360	Highly restricted species selection.
30 gallon	432	Single species, two mild tempered males could possibly fit.
30 gallon BREEDER	648	Only 12 inches tall, however 2-3 males of different species might work.
33 gallon LONG	624	4ft. tank, only 12 inches tall, 2-3 males can work.
37 gallon	360	Highly restricted species selection.
38 gallon	432	Single species, two mild tempered males could possibly fit.
40 gallon LONG	624	2-3 males of different species can work.
40 gallon BREEDER	648	2-3 males of different species can work.
45 gallon	432	Single species, two males can work.
50 gallon	648	3ft length, 2-3 males can work.
55 gallon	624	4ft tank can fit three males.
60 gallon	624	4ft tank can fit three males.
65 gallon	648	3ft tank, 2-3 males can work
75 gallon	864	4 ft tank, great species selection, can house 4-5 males.
90 gallon	864	5 males can work
120 gallon	1152	4ft tank, great selection, 5-6 males.
125 gallon	1296	6ft tank, nearly unlimited species selection, 6 males.
150 gallon	1296	6ft tank, 6-7 males.
180 gallon	1728	6 ft tank, 9-10 males.
210 gallon	1728	6 ft tank, 9-12 males.

* for each male you want to have between 2 and 5 females as well.  You can sometimes add a second sub-dominant male if you have more than 6 or more females.

Compatibility:

When selecting your fish it is important to keep a few things in mind. You should keep fish together that are not going to compete for the same exact niche. You should also avoid similarly colored/striped fish that may be seen as competition for females or territory. Mbuna are Harem polygamists, which means that a single male will try to keep and maintain a harem of females to mate with. It is easiest to select a single fish that you “have to have” and then build tank mates around that fish.

Sex Ratios:

Experience has shown that the ideal ratio is 3 or more Females per Male. Less than this ratio will result with the male wanting to spawn again before the female(s) are ready, he will then harass them, possibly to death. Some species of cichlid are Dichromic, meaning sexually mature Males are colored differently from Females and Juveniles, so buying a group of adults in the correct ratio is fairly straight-forward. Monochromic species are a problem, as the Males and the Females are colored similarly and there are frequently no other easily observable signs to determine sex. To get proper sex ratios with these species you can either buy a sexed group, or buy 6-8 Juveniles and get rid of the extra males as they grow up until you hopefully wind up with the proper ratio.

 

Juveniles vs. Adults:

I personally prefer to raise my own fish from juveniles and see them grow and mature and eventually breed. You may not always get the best fish in the spawn, but sometimes you're rewarded with a show quality fish! Buying adults that have been sexed greatly simplifies things and assures that an improper sex ratio isn’t the source of some other problem you might have. Adults compete for a niche for themselves soon after being introduced, and are often subjected to aggression by the existing fish until they find their place in the tank hierarchy. Juveniles on the other hand are often ignored by the adults until they become sexually mature, and are generally much easier to introduce to an established tank as a result.

Diets:

Mbuna are either Omnivores or they are Herbivores. Some of the herbivorous mbuna are very intolerant of too much protein in their diet and will become diseased if not fed properly. Omnivores are much more tolerant of certain proteins (insects, inverts) but are still intolerant of animal proteins. Omnivores need more protein to look their best, but can survive on an amount that won't threaten most of the herbivores. Know what your fish eats and try to match their diets for simplicity. If you do mix them carefully understand how much and how often to feed treats. Mixing isn't hard; it just takes some planning and fore thought. A good staple food that can be fed to all types of diet is New Life Spectrum (NLS) which justifies its higher cost. I believe that a good healthy variety is the best diet, however so it is important to ensure that treats are limited to only 1-3 times per week. For the strict herbivores (P.Demasoni, Tropheus, etc.)select foods that have less than 35%max protein, less than 7% fat, and at least 5% fiber. For omnivores look for foods with less than 42%max protein and less than 9% fat and at least 5% fiber.

 

Cleaning Crew:

Cichlids are messy dirty fish, plain and simple. A good cleanup crew can ease tank maintenance and keep your tank looking good longer, but they will not replace you. Cichlid aggression limits what kinds of fish we can keep for a cleaning crew, but most of the smaller Synodontis catfish species are a good choice as are Loaches (genus Botia). Shrimp and "lobsters" are not good choices as they must molt and when they do, the Cichlids often shred them. Most crayfish or "lobsters" hunt fish at night while the fish sleep, they are not very good at it, but sometimes they get lucky. I have had some limit experience with Freshwater clams & mussels and they seem to work OK, but they have short life spans in captivity. Its seems sourcing these species is seasonal and pricey. For algae control I prefer the Rubber-lipped pleco (L-187a, L-187b) best as it eats both brown and green algae in vast quantities without leaving huge ropey strings of feces everywhere. Also good for algae control are Bristle-nosed plecos (Ancistrus sp.) which are a very close second for algae eating champ. For hair algae, the Flying Fox is an excellent choice, although they are getting harder to find today. I don't recommend the Gold Algae eater, the Siamese Algae eater, or the Chinese Algae eater with Cichlids.

Non-Mbuna:

There are a few non-mbuna that can tolerate mbuna for tank mates, although nearly all are better off in their own tank. Aulonocara Jacobfreibergi (Lemon Jake) is the one “Peacock” that seems to hold up. Haplochromines have a wider choice; Copadichromis Borleyi, Cyrtocara Moorii, and Protomelas Taelianatus are a few examples. Generally the larger "rugged" fish can hold up, while fish similar in size to the Mbuna seem to have a hard time surviving let alone thriving.

Mbuna Behavior:

Mbuna display some very unusual behaviors that most other families of fish do not. They have personalities that is in many ways similar to most dogs. They will rush up to the glass to greet you when you enter the room or approach the tank, they know their owner and respond differently to strangers, they are highly social and form a hierarchy amongst the group with a “leader” (or “Tank Boss”) and different ranks of sub-dominance for the entire group. For Example: You might have a tank boss that prevents or interferes with another species mating attempts, while that sub-dominant fish may then harass an even lower ranked fish out of frustration.

Territory:

Males setup a feeding territory and a breeding territory. In the wild a males feeding territory can be up to a 22m diameter sphere against conspecifc males (like males), however they will share some of this territory with other heterospecific males (unlike males) though not simultaneously. Their breeding territory is usually closer to an 16-20” sphere centered around a cave or crevice that is aggressively defended against both heterospecific and conspecific males. Each species is different of course, so the exact sizes of territories varies greatly. These are things to keep in mind when setting up an mbuna tank or planning your community. Females either feed independently or in schools in undefended areas. Males will allow females of his own species to graze in his territory when the females are likely to spawn with them and aggressively chased off when not.

Overcrowding:

 

Mbuna are often overcrowded into tanks as a method of aggression management. It is very effective when done properly, and makes for a full tank appearance. It is not a good idea to plan for overcrowding as is often suggested however. The better plan is a well organized community that you overcrowd only as a response to any aggression problems that may arise in your tank as your fish mature. Overcrowded tanks do look nice as displays and can save you headaches with aggression management, just do so wisely. A good plan to overstock when an aggression problem does arise with your initial stock plan would be to add an extra female (or two) for each aggressive male in the tank. This is a better method of overstocking than attempting to introduce a new species. Another option that can work in larger tanks is the addition of a second male. The second male should only be introduced when you have 6-8 females for the alpha male already and he is still aggressive. The new male is sacrificial for the females and other tank mates and will suffer abuse from the alpha male. Keep watch on him in case the abuse gets too severe, but often he will just stay submissive and shows battle scars while being the new source of the aggressive alpha males attentions. I should note that only 6ft and larger tanks are probably large enough for this to work permanently.

Aggression Management:

Cichlids are aggressive fish! You will have fights, fin nipping and even some all out guns blazing battles, expect it. Fish being excluded to an upper corner of the tank or only allowed to hide behind a filter tube however is a sign of an aggression problem. This is why as a cichlid owner it is almost a necessity to have a hospital tank ready at a moments notice. When mbuna decide to they want another fish out, they will kill it quickly so do not hesitate to pull abused fish! At first, it is difficult to know how bad injuries on these fish are before they should be considered severe. I cannot possibly cover all the scenarios you'll run into so to keep it simple remember, If you see bare flesh, blood, jaw or eye injury it is safer to pull them than ignore the problem even a few hours. Homicide can happen in 1-2 hours with these animals in severe cases. There are many ways of managing the various unwanted behaviors that our wet pets display. First is introducing all new fish properly to the tank. You should always add Cichlids in groups of 4 or more so that none of the new arrivals can be singled out, but it doesn't always work out this way. Since all the fish in the tank already have territory marked out, the new guy won't be able to establish himself unless it is a very strong fish and then only after many battles. If you rearrange the tank layout before you add new fish you will break up the existing territories and give the new fish a chance to settle into its new environment. Leave the tank lights off for the day, if possible leave the tank furnishings out until the next day as well. A 24 hour period will give the newest fish time to recover and then when the furnishings are returned it will quickly seek out its own space having the same advantages the previous fish have. The second way that aggression occurs is from a poor selection of tank mates or an improper sex ratio, planning your tank mates well and resisting impulse buys can make things much easier for you. Having too many males or not enough girls will increase aggression levels. Fish seeking to spawn but having no partner can become obsessive over a territory, or even go on a homicidal rampage! A third way aggression can arise is from using too small of a tank for a given species forcing it to claim the entire tank, this typically happens just after the fish become sexually active. Always plan your tank for when your fish are full grown sexually mature adults! Yet another way aggression happens is from an improper diet. A good nutritious diet is fundamental to your fishes happiness so make sure your food matches the diet of your fish. Remember Mbuna are aggressive; try to learn the difference between aggressive but harmless display and signs of impending trouble. To do this you must watch your fish for several minutes each day. I find a good time is right after feeding as they will all be out and give you a good opportunity to do a head count and check for injuries. I also find 10-20 mins right after coming home from work is a great stress reliever. You may even find yourself enjoying the antics of your fish while sitting there relaxing. Feeding smaller amounts 2-4 times a day can help lower aggression levels if you've been feeding less frequently.

Circle Jousts:

These hyper fast duels are often fought between two males, usually conspecifics. The fish are staging and fighting for rank within the tank hierarchy. If the two combatants are of the same species this battle will establish who gets the right to mate with all the gravid females (of the same species) in the tank. Circle jousting is often accompanied by lip-locking. This is a male behavior.

Lip-locking battle:

This is when two fish bite onto the jaws of each other and have a “pushing match” until one backs down and runs away. Often the loser will lose his dominant coloring for a little while. This is usually a male behavior though rarely females will engage in it with each other. This is the ultimate test of a dominant males strength, and will secure a higher rank for the winner.

“T”-barring:

This is when two fish form a “T” to each other. Females often engage in this activity as well as males. It can be part of a mating ritual if between a male and his partner, but more often it appears to be a show of dominance/subservience similar to bowing in Japan. If the dominant fish isn't satisfied with the subservient fish this may escalate into a chase or a joust.

Buccal Puffing:

This is a display of slow circling and inflating the buccal cavity. The Buccal sac is just below the fishes jaw and ahead of its gills. Females will inflate this area to appear larger during staging and dominance displays. This behavior seems to be rarely displayed by males. It is similar to the males version of circle jousting.

Flashing:

Flashing (or scratching) is when you observe your fish rubbing themselves against rocks or the substrate. This behavior usually is a sign of external parasite in most tropical fish, but Cichlids do this infrequently. If, however your fish are doing this constantly then is is a sign of a water quality problem. Usually the pH or hardness has undergone a significant change and the fish are reacting to it. Obviously this is not healthy for your fish so it is important that your new water is matched properly to tank conditions, especially if your changing more than 30% of the tank volume.

Yawning:

This is another behavior that isn't observed in other fish that is fairly common among Cichlids. The fish will open its mouth to its widest point and “stretch out” it fins. It is unknown why they do this, perhaps to keep jaw muscles flexible.

Aggression Therapy:

There are a few ways you can reduce aggression in your tank that have varying degrees of success from tank to tank. First, increasing the frequency of feeding your fish (Not amount, less food more often) can have a positive effect on aggressive fish. Temperatures below 75F can also reduce aggression, but this will also have a negative effect on spawning as well.

Feeding & Care:

Cichlids are fairly easy to keep by most standards. Cichlids are hardy fish and very resilient to disease as long as their water conditions are good. There are a few things we must keep in mind for our fish’s health and happiness.

Choosing a Food:

Mbuna fall into two groups of diets, Herbivores and Omnivores. Some herbivorous mbuna such as P. Demasoni are extremely sensitive to the amount of protein in their diets and will quickly get Bloat and die. Bloat is a catchall phrase for systemic viral intestinal infections or internal parasitic infections and often results in the death of the victim. All herbivorous fish are best fed on a high vegetable based food that has protein contents under 35% minimum. Omnivores should not be fed food with more than 42% minimum protein content. There are many very good foods on the market and there are many more bad ones. Don't just look at the numbers on the labels, but also the order of the contents as well. I feed New Life Spectrum Cichlid Formula and New Life Spectrum Thera A+ nearly exclusively to my mbuna and they have not gotten bloat since I made the switch. I do occasionally feed a treat of frozen foods to my fish to help elicit spawning or just to give variety, but I swear by the NLS. It’s not the only food I use for all my Cichlids; I also use Ken's Premium Veggie Flake for my stricter herbivores which is really fantastic stuff. I also like HBH Cichlid Attack for my Carnivores. When it comes to mixed diet mbuna I recommend NLS! Feeding a good healthy food with good roughage can help prevent your fish from contracting bloat. Garlic is a natural anti-parasitic and can also help protect your fish from contracting internal parasites.

 Spawning:

Happy and healthy mbuna spawn, a lot! Most mbuna spawn about every 45-60 days year 'round with spawns averaging around 25-30, but can reach 45+!!! Most hobbyists enjoy their spawning mbuna at first, and then they get tired of the constant aggression associated with spawning and want to know how to stop them! How do you get cichlid fry? Just add Cichlids and clean water! OK, that isn't completely true, however after 25+ years of experience with these fish I can assure you that for all purposes it is.

Spawning Behavior:

All Mbuna spawn in the same basic manner. The Male will build a breeding site in the substrate creating a bowl shape to help keep the eggs in the center during spawning. The male will swim over to the female when he sees her and vibrates (Appears electrocuted, aka the Shimmy Shimmy Shake) his body in front of her forming a T with her. The male will then try to lead the female back to the breeding site (or any other convenient place if she's willing) and once he gets her to the site, he goes back to the vibrations and lays his anal fin (w/ egg spots) on the spawning site. The Female will then circle around and deposit 1-4 eggs which she circles around and quickly picks up into her mouth. The male then begins to vibrate again and the female attracted to the dummy egg spots on his anal fin will mouth near the males vent as he releases his milt fertilizing the eggs in her mouth. The couple will then continue like this circling and fertilizing until the female is spent. The Male will generally chase her off aggressively once she stops, then will begin looking for a new willing partner. Males also "Joust" over breeding grounds and access to females by Lip-locking each other, and engaging in circling duels. Females can aggressively fight for access to the Alpha male as well as fight over good caves for rearing fry in. Females usually puff up their throats inflating their buccal pouches and form a 'T' but rarely Lip-lock and only infrequently get into circling duels.

 

Post-Spawn:

I have a female holding! Excitement! Joy! Success! That is usually our reactions the first few times we have spawns. Now is the time to ask yourself what you are going to do with your fry if they all survive and grow. Are you prepared with another tank to isolate the holding female and eventually raise the fry in? Once you raise the fry what will you do with them? A few fish is not too hard to be rid of, but 25-40 is a problem. If you’re not prepared to spend the months needed to raise the fry, or you don't have any place to put them once they do grow up, then it is best to let the female spit in the main tank. Most of the fry will get eaten by other fish when spit into a closed cramped environment like the typical home aquarium, and the few that do survive often become personal underdog favorites. One of the things you will want to know if you do decide to raise the fry is who the parents are. I realize that you can't always be sure of this, but you ideally want to see signs of attempted breeding and later a holding female to prevent a growing problem in the cichlid trade, Hybridization.

Hybridization:

There are many arguments about hybrids in the cichlid trade, but my view is that they are bad long-term for us hobbyists and should they be avoided and even destroyed. I know that is a harsh view, but hybrids have highly unpredictable behaviors and their offspring often exhibit different behaviors from the parents making these fish a nightmare for most aquarists to keep with other fish. Any spawn from two fish not of the same species AND same location is considered to be a hybrid. Some people like to create hybrids as a way to make money, or they have dreams of creating Franken fish, or perhaps honest but misguided attempts at "improving" a certain variety. Hybrids are generally frowned upon in the cichlid community much like "mutts" are in the Dog Show world. If you do create a hybrid and you lack the heart to euthanize them, then please keep them in your own tanks and do not let any of them out of your possession. Many people have sold hybrids to pet stores which are then resold as purebred fish leaving the person who receives them with a "mutt" instead of the Pure specimen he paid for. Unlike the dog world, there are no certified lineage papers for fish. The problem is growing and already at least one species (L. Caeruleus) is hard to find pure lines of anymore! There are also many health reasons why hybrids should be discouraged, so for the good of all Cichlidom never give, sell, or trade hybrids to anyone else. If you like your resulting crossed fry and wish to raise them amongst your own tank(s), then go ahead and enjoy them! Please just don't let them out of your tank(s)!

Line Breeding

Line-breeding is an attempt to isolate specific trait(s) in a species and breed only those fish that display those traits back to a parent or another fish with those qualities. Line breeding is certainly mankind manipulating a species for monetary gain, but it doesn't usually destroy the species. (Although it can weaken it significantly. -[sic] Fancy Guppies)

Equipment & Supplies:

To isolate the holding female and rear the fry you will need at least a 10g tank, a quality heater (cheapies vary too much for fry), and some form of filtration. You can use a bigger tank, or different filtration if you have them available, the bigger the better (again). Substrate is optional, and actually makes it harder to keep the tank clean. A couple hiding spots so the female can feel secure are advised, preferably with the opening toward the back of the tank. My recommendation is a good sponge filter with an air pump! For fry, the sponge filter provides a large surface area for them to feed off of, and the low water movement won't splash the fry around in the tank. Sponge filters are not good mechanical filters, but the mother won eat while she is holding fry so you don't feed her producing less waste. Once you have fry, they will eat powdered flake and baby brine shrimp, so it won't matter if the sponge filter isn't very good at mechanical. I also like sponge filters because they are inexpensive and last nearly forever.

 

Fry Removal:

Your female has held for 24-28 days and she hasn't spit her fry. You can remove them yourself so she can start recovering if you want. One method is to pry her lower jaw open with your fingernail while holding her upside down over the holding tank and rubbing her throat or shaking the fry out. This works, but can be very stressful to the fish and can even injure the female. (I know of an incident of death too) I use a technique I developed back in the late eighties after reading about using a turkey baster method to strip fry of small females. I used a kitchen funnel, a white plastic 3" funnel that has an opening of roughly 3/16" in diameter. I place the Female head down in the funnel and with one finger I hold her tail against the side of the funnel, then I pour tank water into the funnel while holding it over the tank (or a container). I wait until the female begins to gasp her gills before pouring, and then I fill the funnel almost to the top and let it back flush her gills. Soon you will see the fry coming out the funnel end and into the tank. Keep pouring until the stream of fry ends, and then check her mouth by carefully pulling the jaw down with a fingernail or toothpick. (Or you can wait for her to open up during a gasp, but she won't open if she still has any fry left in there). Mbuna fry are quite large at release, about 3/16" long and 1/8" inch wide.

Fry Care & Rearing:

Mbuna fry are generally very easy to rear and they are very resilient fish like their parents. Providing them with extremely clean conditions is needed to prevent stunting or disease, so twice-weekly water changes of 15% are recommended on fry tanks. The fry can eat powdered flake food and Baby Brine Shrimp for the first week and then I switch to just crushed Flake and New Life Spectrum Growth Formula which comes in 0.5mm pellets so the fry can swallow them. Depending on the species, fry can take from 3 months to 9 months to reach the 1.5" size range which is about as small as the fry can be and survive shipping them off to another owner / LFS. In many species 1.5" is when the juveniles start to reach sexual maturity and by 2" most of the fish will be mature and you will need to separate them. At around 3/4" in size I prefer to transfer my fry to grow out tanks which are larger than the fry tank. I change water weekly on grow outs tanks, but I increase size to 50% since the juveniles can handle large changes better than fry.

Thank you!

I wanted to say thanks to a few people who have lent me support or taught me valuable lessons. First to my Dad for keeping a 10g fish tank that got me started, and bought my 20g when I was aged 12. To my roommates for putting up with all those tanks and spills. To my Wife who against all her better judgment allows me to flood the basement on a regular basis. To my Son for trying so hard to learn the Latin names and his boundless enthusiasm at feeding time. Lastly to CichlidForums who's friendships and knowledge has been a guiding hand.