Tank Troubles

[kojote]

i have kept fish for many years, never really had issues up until i moved and got a new tank, which i have had for several years. since moving, everything that isn't a goldfish dies in my 20 gallon tank from unknown causes. i have yet to get my tank water tested at a pet store to determine the pH levels and such, but i feel that maybe my tap water has too much chlorine and calcium and that more sensitive fish can't handle it. recently i bought 4 mollies and 4 platys, and all died within a few days of introducing them to the tank except for 2 of the platys, which are both female. they are still alive, though they mainly hang out towards the bottom at the back of the tank behind the plants as though they're shy, i'm not sure if this is normal platy behavior since i've never owned any before.
 
so, my question is: what should i do to determine what's killing my fish? is it the goldfish raising the pH levels? the calcium and chlorine levels in the water? what could i do to get rid of the toxins in my tap water if so? any other advice for caring for the remaining platys?
 
tank size: 20 gallons
tank temperature kept at: 75-78 degrees fahrenheit
tank inhabitants: 2 goldfish (standard feeder-fish type, carnival-won, have had them for several years) and 2 female speckled platys (have had for 1 week as of today)
 
thanks in advance!
 

 

[eaglesaquarium]

Welcome kojote!

 
 
Platys are not shy by nature.  They are gluttons, and will normally be swimming all over the tank looking for anything to eat.
 
 
(I hate to be the one to tell you this... 
The bad news is that the goldfish really can't be kept in that tank at all.  "Fancy" goldfish should be kept 1 per 20 gallons, or an additional 10 gallons per additional fish.  The carnival feeder goldies are usually 'comets' or similar, which I prefer the appearance of... but take a look at this article:
http/www.fishforums.net/index.php?/topic/417799-goldfish-for-beginners/

 This is a picture of 'fluttermoths' common goldfish.  She placed this fish in a 14L tank to illustrate its unsuitableness for long term living quarters.  
 
Also, goldfish are 'cold water' fish.  They should not be kept in a heated tank.  Heated tanks increase their metabolic rate, causing them to eat more, poo more and die younger.  They are best kept outside, in a pond whenever possible, but rarely are.  At worst, they should merely be kept at 'room temperature' in an aquarium.
 
 
I'm not sure what the major problem is with the other fish at this time, but there are definitely some issues with your tank - sorry.

 

[kojote]

thank you for the feedback, i appreciate it! i took my water in to be tested and described my tank and its inhabitants and the clerk said the same thing, goldfish should not be kept in this tank or with tropical fish, so i am going to rehome them as soon as i can. i also bought water conditioner, as well as a chemical that adds the bacteria lost during water changes, and the person i spoke with at the pet store gave me some test strips to monitor the quality of my water and even with the water change i still have dangerous levels of nitrate, so yes, as sad as it is, my goldfish need to be rehomed. the platys are still doing remarkably well though, and seem to be coming out of their shell a little though one nips and chases the other sometimes. thank you again for your help, i appreciate it

 

[eaglesaquarium]

Do you know if you have a male and female platy or two males?


This type of behavior is normal for platies. They are 'amorous' little things, as well as gluttonous. Males will constantly be jousting for mating rights.... and if there's a female around, males will constantly be harassing the female. (Generally, the proper ratio is 2-3F for every 1M.)


A male livebearer's anal fin is called a 'gonopodium' and it has the appearance of... well, a male appendage. Meanwhile, the female livebearer's anal fin is still the shape you would expect for a fin - completely fanlike. At times they will both 'clamp' their fin, so take your time observing to determine their gender.

Male platy:

 
Female platy:

 

[kojote]

i'm fairly certain they're both female, yes, as they both have the same shape of fin on their bellies but the one being picked on is slightly smaller and i'm to understand that all plattys appear female until fully grown? so maybe the small one is a male and i just don't know it, but they both appear to be female.

 

[eaglesaquarium]

Yes, they appear female until they 'mature'.  In some livebearers (specifically swordtails, though platies and swords are so interbred now that I don't know that you can find a pure variety of either any more), even mature males that are non-dominant will be suppressed in expressing male traits until the dominant male is out of the way.  So, some 'males' are very late in developing - which gave rise to the notion that they were changing gender to some folks.

 

[kojote]

right, gotcha. so i'm not gonna know until i know, seems like. how long does it take for a platy to become fully grown?
also, i rehomed the goldfish and already the platys are beginning to become more active. i did about a 30% water change and the nitrate is still a little high, when should i do another, and what percentage should i remove?

 

[eaglesaquarium]

How high is the nitrate?

 

[kojote]

i have the test strips for it and
these are my levels: http/i.imgur.com/ycG39xxh.jpg
and this is the scale im using to measure it: http/i.imgur.com/sqafcAR.jpg

 

[eaglesaquarium]

That's not that high at all, honestly.  Nitrates should be aimed to be kept about 40ppm higher than your tap water.  Lower is certainly better, but 0 can actually lead to trouble too, ironically - blue-green algae (which is actually a bacteria).
 
 
Anyway, I'd leave the tank as is, and do a 50% water change next weekend.  Then you can settle into a nice routine of 25% weekly.
 
 
In my own case, I try to do 25% weekly, 50% monthly, and semi-annually a 75% water change.  
 
 
The larger changes end up happening in the fall and spring - so that the excess water and nutrients end up in my flower bed outside my house.   This provides nutrients in the spring to feed my plants all summer... then to replenish in the fall, and then again in the spring...  it works.  My flowers are usually very happy... (and they also get the other water for as much of the year as possible, as long as the temps aren't below freezing outside).

 

[kojote]

oh really? that's a relief, i was very concerned about my platys--wouldn't want them to sit in bad water, now that i know it's actually bad. thank you! i'll do another water change next weekend.

and, yes, that's what i do with my water when i change it, i water the grass and flowers which works out nicely since we are currently having an awful drought and need to be as conscious of water use as possible.

also, now that the goldfish are gone and my water levels aren't bad, how long do you recommend waiting before adding more fish? i'd like to get a few more platys, possibly a few mollies and some algae-eating creatures but i'll have to research those.

 

[eaglesaquarium]

It seems that this tank has been up and running for a long time, so it would seem that you don't need to wait long at all.  I'd suggest waiting a week... just to make sure that things settle in with the platys, then do the water change.
 
Then you could add some more fish.  Platys are actually fish that will graze constantly on algae that they see, especially on plants, etc.  (remember they are gluttons. )  And they are omnivorous which means that the algae is a good supplement to their diet.  
 
 
The tank is probably a bit small for mollys.  Is this a 3 foot long 20 gallon, or a 20 gallon tall?
 
 
More platies would certainly work... and for algae, I'd recommend either some shrimp or snails.  Again, the tank is too small for 'traditional' algae eating fish.  Otos require numbers and a good supply of algae... which means lots of surface area.  Plecos (even the smaller ones) are too big for a 20 gallon tank.   But, Amano shrimp are great algae eaters and quite large.  They won't be messed with by the platies, and might even help with fry control should they have any...  Red cherry shrimp are very colorful, and will readily breed in your tank, and the shrimplets might provide nice meals for the platies as well.   Nerite snails are likely the best algae eaters there are and some have quite ornate shells.
 
As for other fish options, guppies and endlers would work well... as would any rasbora specie and most tetras.

 

[kojote]

my tank is the latter, approximately 3ft long and 20 gallons.

thank you for the recommendations! i think maybe next weekend after the water change, i'll wait a day, and then see about heading down to the pet store to scope out my options. i was thinking either shrimp or snails as algae eaters, yes, and cherry shrimp seem to be a good option if they'll also provide food for the platys. thank you again for your help, if you have any other advice i'd love to hear it. it's been a very long time since i've had anything but goldfish so i can use all the tips i can get!

 

[eaglesaquarium]

Oh... one thing on having shrimp... they LOVE plants to climb around in.  The best stuff for them is probably java moss, which can get a bit untidy at times, but its an ideal hiding spot for the shrimp, nursery for fry and/or shrimplets and a great place for them to graze.  A small clump should be sufficient...
 
And if you want to try your hand at some other easy plants that need no real special attention, try to grab some anubias and/or java fern.  Both need to be attached to something and their rhizome kept out of the substrate and in the water flow, but they are GREAT additions to your tank, and again, will provide cover, oxygen, nitrate relief (very minor, they are slow growers) and a 'natural' feel to the tank.  They don't need anything special.  Whatever light you are using for viewing your fish will be sufficient to give them light.  The CO2 from the fish will be sufficient, and the fishy poo in the water column will be enough to fertilize them.  They are truly the ideal plant for people who don't want to do anything with plants... and if you later decide to go with some other plants, they blend in perfectly and add some texture!

 

[kojote]

excellent! thank you very much, i'll be sure to bear all that in mind.