Freshwater Stocking Question, Corydoras and Platy Sel.  11/26/08
Hello W.W.M. Crew!
<Jake>
I am trying to help some friends with their aquarium, and would appreciate some stocking advice. Here is the setup: They have a 20 gallon aquarium, that is 24 inches long. It has ordinary (non-calcareous) aquarium gravel, with plastic plants, and is filtered by a Hagen AquaClear, that turns the water over 7 or 8 times per hour. I have that filter stocked with Hagen's bio-ceramic media and synthetic filter floss. These ladies follow proper procedures for cleaning the filter and doing weekly, partial water changes.
They vacuum half the substrate each month.
<I'd do this every week or two>
They also know how to feed properly, without over-feeding. Their tap water comes out of the faucet at ph 7.8, and is hard, but not VERY hard.
(I can't recall the dh numbers right now.) They use Cycle on their tap water, and allow it to sit for three days before placing it into the tank.
This tank and filter are already "mature"/cycled, as it has been up and running for a year, with some other fish. (Those fish will NOT be in the tank, though, with the new fish.) After much consideration, trying to agree on fish that would be interesting for them, but appropriate for the water conditions and size of the tank, we have agreed that they will stock with Corydoras and female platies. So here are my questions: If they stock five Corydoras, then how many platies would be the most that they should stock,
<A dozen or so... A comment re the all female selection. Very likely some individuals here will reproduce... these and many other livebearers are able to "store" sperm in their tracts... So, unless isolated from males at a very small size...>
and are there varieties of Corydoras that should be avoided, because they will not adapt, (as well as others), to the hard water?
<There are some that are better than others... you could do the LONG read on fishbase.org re the genus' constituents known natural ranges here... Or "just shoot for" tank-raised species/specimens... as all these will "stretch" to this pH, not too hard water>
Their water parameters will be kept at healthy levels, but I am concerned about things such as "psychological space/crowding" for the platies. Also please tell what you believe the IDEAL temperature would be for this mix of
species. Thank you, so much, for what you do! Have a great, fishy day!
Jake D. (Wisconsin)
<And you as well Jake. Bob Fenner>

Re: Freshwater Stocking Question 11/26/08
THANK YOU, Bob! And I would like to tell you, quickly, that it is because of YOU and the W.W.M. website, (and the effect that it has had upon how I keep fish), that I originally stepped forward to ASSIST these ladies, when their tank looked like a failed chemistry experiment, and they were about to leave the hobby. It has been a privilege to be able to help them to succeed, and to remain in this great hobby/pursuit. I continue to look for opportunities to assist others in a similar way. THANK YOU, one hundred times, for all that you do. Have a blessed Thanksgiving! Jake
<Ahh Jake, deeply gratifying. So glad to find ones efforts inspiring others to help. Cheers, Bob Fenner>

Adding baby platy to tank   12/2/07
I have a 10 gallon tank in my classroom with one male and one female red wag platy. I thought I had all females when I bought them from the fish store because the sales clerk told me they only had females, but evidently she was wrong. After looking at pictures on the internet later, I realized the smaller one was most likely a male. Anyway, while doing a water change a couple months ago, I found one fry. The fry stayed in a breeder net (box-shaped) within the 10 gallon tank for awhile but then I set up an Eclipse 3 gallon aquarium for him/her so he'd have more room. Now he's almost 2 cm long now. I want to put him/her in my 10 gallon tank with the other 2 platys now so I can keep the 3 gallon tank for any new fry I may find.? Will the other two platys pick on him/her since he would be the stranger in their territory??? Is there some particular way I should add him to the tank so he would not be picked on by the grown platys??
Thanks!
Carolyn
<Carolyn, Platies are essentially schooling fish and the more the merrier. The only possible problems come from males, which will sometimes chase one another. If there are a surfeit of males, the males may also harass the females in the anxiousness to mate. That's why experienced Platy keepers always recommend keeping two females for every one male -- it's the only way to ensure peace, in small tanks especially! In fact, in small tanks, I'd always recommend keeping just female Platys, since they're no less attractive than the males. In any case, Platies are easy to sex: Only females have triangular anal fins; males have rod-shaped intromittent organs called gonopodia. If your store clerk can't tell the difference, he/she must have very poor eyesight! One good idea with Platy tanks (and livebearer tanks in general) is to use lots of real/plastic plants, especially ones that float at the surface. Not only to they provide hiding places for the fry, they also allow picked-upon fish to get out of the line of fire when they want to. Cheers, Neale.>

Stocking first tank with platys   9/3/07
<<Greetings. Tom with you.>>
I'm new to this. I have set up a 10 gallon aquarium in my classroom and, after reading a bunch of stuff on the internet, I think platys would be good fish for me.
<<Quite possibly.>>
I do not want fish fry, though, as I think I will be challenged enough just trying keep my aquarium in good condition without worrying about raising babies and what to do with them.
<<You can always let Nature take its course but I understand your reservations.>>
So, I either need to get all male or all female platys.
<<And hope the females, if these are purchased, haven’t mated before you get them. ;) >>
I was thinking all male would be the best choice since there is the possibility that a female could be pregnant when I got her or that a immature female might be misidentified as a male.
<<Exactly.>>
However, I want my fish to get along with each other. Will I have aggression problems by having all males?
<<Potentially, yes. Even without females to vie for, your males will likely attempt to establish a “pecking order” among themselves. Given the temperaments of these fish, however, I shouldn’t think this would pose too great a problem.>>
Also, what would be the best plan for stocking my tank? Should I get 3 platys to begin with and, after the tank has cycled for a while, then get 2 more?
<<First, don’t add any fish until the tank has completely cycled. In a classroom setting, this is a wonderful opportunity to educate your students on the proper way to establish an aquarium. No need to turn this into a course in Science but the question will almost certainly arise as to why the tank has no fish in it. You might take a look at these articles: http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm
http://www.wetwebmedia.com/FWSubWebIndex/fwfiltration.htm
When you’re ready to add your fish, it would be best to add the five at the same time. Though not noted for being territorial in the same fashion that some other species are (Cichlids, for example), adding all of them together will start all on a level playing field, so to speak. Another means of alleviating possible aggression.>>
Is a total of 5 platys too much for a 10 gallon tank?
<<No. You might even consider adding a few of the Corydoras species – belonging to the Catfish family – as these fish, along with being a particular favorite of mine, are non-stop scavengers and will aid in cleaning up uneaten food. They’ll need their own diet, of course, but will continue to scour the bottom of the tank nevertheless.>>
Thanks!
<<Good luck with your venture. Tom>>

Re: Stocking first tank with platys   9/3/07
<<Hello again, Carolyn.>>
Thanks so much for getting back to me so quickly!
<<Happy to do so.>>
I can't wait for my tank to cycle so I can finally add some fish!
<<I understand completely.>>
About adding the Corys, what would be a good number to get for a 10 gallon tank if I do have 5-6 Platys?
<<Since the Corys will inhabit the bottom of the tank, for the most part, and not really compete with the Platys for food at mid-level, you could easily add five or six. One admonition? Hold off for a couple of weeks before adding the Corys after the Platys have been introduced. Two reasons for this. First, you don’t want to overload the bio-colonies by adding too many fish at one time. Second, you’re not set up for quarantine and a couple of weeks will give you time to make sure the Platys are in good health. (Corys are “scaleless” fish and would require a different treatment regimen should something unforeseen arise.)>>
If I get more than one, should it be a combination of male and female?
<<Corys are very social toward each other – the more, the merrier in the case of these fish - so getting males and females strictly for “companionship” isn’t truly necessary. Likely that you’d wind up with some combination of male(s) and female(s) anyway.>>
I don't want to overcrowd my tank with fish.
<<You won’t be overcrowding, Carolyn. Keeping up on regular water changes (50% or better each week) and maintaining your filter properly will easily handle the numbers of fish you’ll have. The Platys and Corys are both smaller species of fish that you should have little, if any, difficulty keeping well in your 10-gallon tank.>>
Carolyn
<<Tom>>

Re: Stocking first tank with platys (follow-up) – 09/05/07
<<Sorry for being a little tardy, Carolyn. Holiday’s over and it’s back to the day job!>>
Thanks so much!
<<You’re quite welcome.>>
I meant to ask you what to add first but forgot so I'm glad you put that info in there!
<<By way of explanation on this – and for the future – Platys are much easier to detect problems with than the Corys would be. I’ve kept Corys for years with varying degrees of success (some varieties are simply hardier than others) and rarely have I been able to successfully treat one with an illness. They simply don’t “display” illnesses the way other species of fish do. A Platy laying on the bottom of the tank is a sure sign of trouble. For a Cory, this is totally normal. They don’t tend to “clamp” their fins in the more obvious manner of other species which makes early detection of health issues problematic. The upshot here is that I’d rather see you add the Platys first to “get your bearings” and add the Corys afterward. They’re extremely social among themselves and oblivious to most anything/everything else in the tank (other than what they can scavenge). Aside from poor water conditions/quality, there’s not much to stress these little guys and gals.>>
Carolyn
<<Tom>>

Platy m/f ratio   5/10/07
Over the course of adding fish a few at a time to my tank, I decided to get some platies. At the time of purchasing the platies, I read that you should have at least 2 females for each male, so my intent was to buy 2 or 3 females and one male. However, the guy at the fish store said he couldn't find any male platies in the tank, so I just got 3 females to start with, with the plan of getting a male later.
So, today I went back to get the platy and some other fish, and after having the sexing of platies explained to me and arriving back home and examining my fish, I am fairly sure that 2 of the 3 "females" I bought previously are actually males!
<Mmm, yes... happens... can/do change sex... where there is a need, opportunity>
So now I have 3 males and 1 female... I know this is not optimal, but I'm afraid that if I buy the 5 additional females needed to get the ratio right, my tank will be overcrowded. Current inhabitants are: 4 dwarf gouramis, 2 African dwarf frogs, 4 platies, and 4 black-/white skirt tetras in a 20-gallon tank (not planning to add anything else other than possibly platies).
Should I get some more females, and if so how many?
<I would just stick with what you have here>
Should I try to get the fish store to take back some of the males they sold me (it's not like I have proof of what they told me about the sexes)? What is likely to happen if I leave the current platy sex ratio?
Thanks in advance for any advice,
Suzanne
<Likely all will be fine here with the "batch" you have, the setting... I would leave this mix of platies as is for now. Bob Fenner>

Platy question   2/9/06
  I recently bought a 5 gallon aquarium (I've had aquariums most of my life, but I had to move and had to leave my old one behind.) I have 2 platies to start with, and as it turns out they are both males.  One is a Mickey mouse platy and the other is red tail sunset platy.  The red tail sunset has taken to picking on the Mickey mouse platy.  The Mickey mouse platy doesn't seem to care, he just swims off, and he gets plenty of food.  I'd like to stop the red tail sunset from chasing him, so I'm going to buy more platies...however, I don't want babies.  
  If I buy a few more males, will that disperse the territorial behavior that I think I'm witnessing?
<Quite possibly, yes>
Will they all decided to just live peacefully or will they all pick on one another?
<At some point in crowding, the tension should be diffuse>
I'm willing to buy a few females, but I really don't want a bunch of fry to deal with.  I know that the platies are cannibalistic and will eat their fry, so I guess I could just let "nature take its course," but obviously that seems rough.  What would you recommend, that I buy more males or some females?
<Up to you>
  Also, should I be using an air pump for a 5 gallon tank?  They seem to be doing okay without one, but I do have one I could use.
Thank you so much,
Lindsey
<Well, do need aeration, circulation from some source... Bob Fenner>

Platies, all male stocking?  - 2/4/2006
Hello...I'm a new at this...I have a new 15 gal tank that is ready for adding more fish....I like platies for their ease of care and color....I am
not interested in breeding....Can I put just males because they are smaller and brighter color or am I messing with mama nature by not having the
recommended male and two females....
<Can just have all males>
I realize this question is a bit basic but like they say "No question is too stupid to ask"....Thank you for your consideration....Bill B.
<Mmm, nope... All earnest questions are welcome... discourtesy is not. Cheers, Bob Fenner>

Red Mickey mouse platy
I just purchased a red Mickey mouse platy, and I have a 3 gal. aquarium.  I was wondering how many platies can I have in my 3 gal. aquarium.
<<Basic rule of thumb for freshwater is 1 inch of fish per 1-1.5 gallons of water. The 1 inch should be based on the adult size of the fish, not necessarily on the size it is when you buy it. This rule changes depending on the nature of your fish but will work as-is for Platies. Platies reach an adult size of approx 2 inches, so going with that, I would put no more than 2 in your 3g tank. You may want to also make sure that you get two of the same sex as Platies do tend to breed quite easily and while the parents will eat most of the babies it's still possible for your tank to get overrun. Ronni>>

New tank and platy choices
Hello,
I recently got my daughter a tank (Eclipse 12 system) for her 11th birthday (Aug. 18)- added water and Cycle and let run for 4 days. Her Aunt then got her fish (wrong kinds for a beginner tank- 3 hatchet fish, 3 cardinal tetras, an Oto and a frog). Well, 2 days ago the last tetra died. I did a 90% wc, re-filled and added Bio-Spira yesterday. Today I got her 2 platies (turns out one male and one female). My question is: should I get another 1-2 FEMALE platies- and if so, how to hand the fry that I am sure will eventually show up? I have some live grass and java moss in the tank, so I guess the fry will have some places to hide, but I do not have any other tanks at this time. Also, how do you get a "nursery tank" set up and cycled with out any fish in it constantly? Sorry for the long post- but don't want to got through any more "funerals"! (I do w/c about 1x week and do test for ammonia, nitrites, and nitrates about 1-3 times a week).
< Another female will take some of the stress off of the single female by the male. If you want to save the fry then you need to set up another tank. The fry from the platies are going to be small and either eaten by other fish or sucked up into the eclipse's powerful filter intake. If you see the female is pregnant from the large size then you can always put he in a breeder net device designed to separate the mother from the fry. They can then go into another tank until they are large enough not to be eaten by the adults. In a new tank with the fry you can do small water changes to keep the ammonia in check. Add some gravel from the main tank to get things going.-Chuck>
Marcell (Alaska)