Sail Fin Mollies and Fish Tank

Question
QUESTION: Hi Chris,
My tank is a 33 litre present (JEBO R338 - pump came with it: R338) given to me about 4 weeks ago, I have been told that I am able to hold at the very most 8 fish in my tank, hence was helped to choose 4 Guerramis, 1 small catfish (used for "cleaning" [small]), 2 sail fin mollies and a swordfin.
The pH in my tank continues to become acidic, but have been told that my ammonium levels are probably high, hence I have recently bought AMMO-Lock, but I have never done anything or know what to do about nitrite.
I change the water once a week and at most 1/3 of the water is exchanged. I had added Multi-Care to the water in the 2nd to 3rd week instructed because of unknown disease (recommended by local aquarium shop owners)
As you can see, I am no expert but rather an amatuer...
I really hope you could help me, since I seem to be clueless as to how to maintain my aquarium, I have replaced my original heater with another heater that has a preset temperature marking and have added a bag of carbon into the filter to clear the multi-cure and the water.
But the fish in my tank are somethings really inactive or scared... Is there something I need to do?
Also, just recently, my female Sail Fin Mollie has a certain swelling on the rear muscle area of her tail, it has caused her to be unable to use her tail (right behind her fins on her belly). I do not know if this can even be fixed, but the swelling seems to look like a lump... I cannot really explain it, but if possible I would hope a picture could be sent to you so a more accurate solution could be found...
I regularly check my pH and aim to get the pH around 7.5 mark, and always add a pinch of salt after each water change along with stress coat and stress zyme.
I feed them twice a day with normal flakes introduced by local aquarium and sometimes bloodworms...

ANSWER: Hi Allan;

Your maintenance is just fine, but tanks often need more attention in the first few weeks. Your tank is still in the break-in period. It actually has too many fish in it to get it safely through without really stressing the fish though. Fish waste toxins rise during the 6 to 8 week break-in so the more fish you have, the higher the toxins. The toxins cause burning of the skin, gills and eyes as well as general ill health and hiding. Sometimes the fish  act skittish or nervous. Once the toxins go down, the fish usually recover just fine. Make a daily water change of 25% for the next 3 or 4 days to help the fish feel better. It shouldn't be long before the tank fully breaks-in. Here is a link to my article about new tanks and what's going on in there;

http://www.xanga.com/Expert_Fish_Help

Don't be concerned about the pH. The fish will get used to where it is that your tank likes to be. Trying to alter it with anything other than partial water changes can be very traumatic and even deadly to the fish. What we should look for is a stable pH, not a certain measurement. Even fish that are supposed to prefer a certain pH will thrive and even grow and reproduce in pH that is far from what is said to be "ideal" for their breed. As long as it stays at a stable area and this stable area is within 6.2 to 8.0 or so, it's really not a concern.

The lump on the sailfin female could be an infection that has developed from the stress of the toxins. It would be helpful to isolate her for treatment. Find an antibiotic medication that absorbs into the skin or give her a medicated food. The two antibiotic medicines I know of that absorb are "Kanamycin" and "Maracyn Two". See what your local fish store has available. It is usually best to isolate and treat sick fish individually. Using medicine in the main tank causes fish that aren't sick to be treated, the filter removes some of the medicine, and it can make a horrible mess too. Get a small tank that you can keep handy for times like this. It only needs lights, a heater and bubbles. No rocks, no decorations and no filter. Change 25% of the water in the isolation tank every day to keep it fresh.

You may want to look into a larger tank soon too. Your tank having a capacity for 8 fish is only partly correct. The general rule for community tanks is; "One inch of fish per gallon (or roughly 2.5 cm of fish per 4 liters)." However, this rule applies only to fish that stay small and don't tend to be messy. You need to know the adult size of each fish so you can calculate a safe population for your tank. They are usually pretty young when you first buy them so they will have some growing to do. Your types of fish actually get pretty large. Sailfin mollies get to be about 5 or 6 inches (about 13cm), swordtails about 5 inches (about 12cm) as adults. Both those types really shouldn't be in any tank smaller than about 80 liters so they have room to move around. They will have live babies too so you will need room for their future family members as well. ;-) Here are profile pages about sailfin mollies and swords;

http://www.fishprofiles.com/files/profiles/376.htm

http://www.fishprofiles.com/files/profiles/559.htm

http://www.fishprofiles.com/files/profiles/560.htm

There are lots of different catfish and gouramis, and some get really big so check out the same site for those here;

http://www.fishprofiles.com/profiles/list.aspx?term=catfish

http://www.fishprofiles.com/profiles/list.aspx?term=gourami


I hope your fish feel better soon. Let me know if you have more questions...

At Your Service;
Chris Robbins

---------- FOLLOW-UP ----------

QUESTION: Thanks Chris;
That really helps, but I have just found out that my fish arn't exactly what i called them, they are 2 Sail Fin Mollies, 3 dwarf guerames, 1 swordfin and 2 albinos... are they still going to grow too much for my tank?
Also, do you think I should change to coral tanks? where i am thinking to put 2 clown fish and a coral in the 33 litre tank... or should I just keep with my tank atm?
Also, I am wondering, could I just buy something like a goldfish bowl and put the Sail Fin Molly in there or would that increase the stress on her?

Answer
Hi Allan;

The tank is just too small for mollies and swords. They need more room, such as a 20 gallon (about 60 liters)or larger.  Yours are still young and will be growing to those sizes suggested in the profiles. It's really only big enough for the 3 gouramis and the albino cats. Read through the sites I gave you to see their future sizes and what size tanks they actually need. It's difficult to keep fish healthy in tanks too small, especially for a beginner. This is why it's so much better to start with a larger tank of 80 liters or more. You have a lot more room to make mistakes in. The smaller amount of water you have, the quicker you have to detect and solve problems that arise.

The molly needs a filter, a heater and at least 30 liters all to herself if you want to separate her. Then you will need room for the babies. They will grow and need bigger tanks too.

I am not an expert in saltwater but I kept them successfully years ago and I can tell you it can be more difficult, sometimes the equipment is different and the fish are more delicate than the ones you have now. It's also much more expensive. I think your tank is far too small anyway. It's certainly up to you, but you would have more success in saltwater in the future if you can learn more by keeping freshwater fish first. You have just begun and there is a lot to learn and become experienced with. I find it's better to do so on less expensive and less delicate fish. Consult with the saltwater experts for more information about it. Here are more helpful links too;

http://freshaquarium.about.com/od/aquariumstartup/a/newtankmistakes.htm

http://fins.actwin.com/mirror/begin.html

http://fins.actwin.com/mirror/sbegin.html

http://www.firsttankguide.net/myths.php

http://www.firsttankguide.net/size.php

http://freshaquarium.about.com/cs/beginnerinfo/a/fishcalc.htm

At Your Service;
Chris Robbins