Spinning Mollie(s)

[Burkey]

Recently we have had two Mollies on seperate occasions begin spinning in sort of a cork screw fashion. The first died and the second began sometime today. Tank is 20 gal. and tests O.K. except for slightly low alkaline. Any thoughts will be appreciated. Thanks in advance.

 

[FawnN]

What is your set up? How many mollies? What other fish are in with them?

Tank is 20 gal. and tests O.K.

Does this mean you have tested your water parameters and have 0 ammonia, 0 nitrites and minimal nitrates?

Mollies are brackish water fish and unless you have some salt in the tank for them, they are very prone to shimmying, fin rot and other problems.

If possible, I would put 1 Tbsp for every 5 gallons of water in the tank. But first, I need to know what else is in there since some fish can not tolerate the salt.

 

[Burkey]

Numbers and other info.

Currently the pH is 6.6, the Ammonia is 0 and Nitrite is 0.
Using the quick dip test strip my reading for Nitrate is around 160-170. In an attempt to lower the Nitrate I introduced a Nitrate pouch in between the carbon filter and the edge of the filter basket about a month ago.

As for salt I've been pretty good about administering it each time I do a water change (about a gallon or two each week.)
How do I know when I have too much salt in the tank? We have "salt creep" happening on our cover and on the tube for the 6" airstone.

Thanks again for your help.

 

[TheManichaean]

160 ppm is very high. 40 ppm is really the highest level the fish should be exposed to. I suggest PWC's every few days to bring that level down. Good luck!

 

[FawnN]

Nitrate is around 160-170

Oh my goodness. That is extremely high. I would suggest you do 15% water changes everyday and if that doesn't work, I would suggest you 10% water changes twice a day if you can.

Once in the morning and once at night. Just remember that to reduce the stress on your fish, smaller, more frequent water changes are best.

What is your set up? Do you have any plants? How many fish do you currently have in your 20 gallon and what sort of fish are they?