Placo

Question
I have a 2 y/o, 11" placo who has been in a healthy, established 55 gallon tank with 3 Bala Sharks and one albino oscar.  The placo seems to be having seizures - he shakes, shudders and has moments of crazy swimming, and I can't figure out why.  The tank is fine on all chemical levels, well airiated, temp is 81 degrees and filters are clean.  Any idea what's wrong?

Answer
Hi Rebecca;

Check the level of nitrates. You are probably checking pH, ammonia and nitrItes now, but get one for nitrAtes too if you aren't testing for it. Water changes are the only way to lower them. In a crowded tank with messy fish like yours it is common to see it high. It can be up to 40 ppm safely. A clean filter might seem like a good thing, but too clean and you lose your beneficial bacteria. That causes spikes of toxins (ammonia and nitrite)that can make them sick too. All those fish get a foot long and will need more room eventually. Balas are very hyper and may need a bigger tank at a smaller size than the pleco or oscar does.

Plecostamus are more sensitive to water chemistry and dirty gravel than your others are. Vacuum the gravel too so he isn't exposed to waste down there. Your tank needs at least a 25% to 50% water change weekly to keep everyone healthy. It is also possible he has a tumor or an infection. Look at his belly and see if there is any redness or unusual areas. He would need to be treated with medication and more water changes if it is an infection. Let me know if you find anything else abnormal.

At Your Service;
Chris Robbins