Goldfish staying near the bottom of the tank

Question
I have some goldfish and got 2 new small algae eaters cause we cleaned the tank and the old one died. I now notice that the goldfish are staying together at the bottum of one side of the tank and they have red (blood like marks)on their under bellies. What is causing this and what can we do about it.  

Answer
Hi Africa;

I would suspect bacterial infection, or "New Tank Syndrome" toxins are burning them. The algae eaters could even be sucking on them and causing injury. Or, a combination of these.

You didn't mention what size tank you have, how many goldfish are in there and what size they are, but "New Tank Syndrome" will make fish very ill if there are too many fish in the tank too soon. Cleaning it all out well is the same as starting over with a brand new tank so it will go through "New Tank Syndrome". Beneficial bacteria that will grow in the filter and in the gravel needs time to fully develop and consume fish wastes. Until that happens, fish waste toxins can rise to very harmful and sometimes lethal levels. This process takes about 6 to 8 weeks. Make a 25% water change right away to help them feel better. Here is a link to my own page that explains more about new tanks and the process they have to go through;

http://www.xanga.com/Expert_Fish_Help

Goldfish are very messy fish that each need at least 10 gallons of water to live in. In other words, if you have 3 goldfish, you need a minimum of a 30 gallon tank just for the goldfish. It would need to be even bigger than that to make room for the algae eaters. Here is a web page about goldfish care to help you know more about their needs;

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

Also read the following web page to see if they have a bacterial infection known as "Hemorrhagic Septicemia". It causes lethargy and spots that look like broken blood vessels;

http://www.geocities.com/shtinkythefish/diseases/septicemia.htm

If your algae eaters ever seem to attach themselves to the sides of the goldfish or chase the goldfish, it would be best to separate them. You didn't mention what kind the algae eaters are but some can be very aggressive, especially at night. Sometimes if there isn't any algae to feed on yet they will suck the goldfishes' slime for food.  

I really think what's going on is a combination of 'new tank syndrome' and hemorrhagic septicemia. Make some partial water changes and use Maracyn-Two from the fish store as recommended in the article.

I hope they feel better soon...

At Your Service;
Chris Robbins