Disease in tank

Question
Hello Chris,

I greatly appreciate the response - I do have a follow up- I forgot to mention that I also have Danios and somewhere I read not to let the temp go above 78???? Is this true?

Also - Will the fish die because of excess ammonia in the tank without the carbon?

Thanks again,
Ed
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The text above is a follow-up to ...

-----Question-----
Hello,

We have had our tank for more than a year. It is filled with guppies, tetras and a Pleco. It is a 30 gallon tank with 1 30gal capacity filter that sucks from the bottom, and a 10 gal capacity filter that sucks from the top.We are overpopulated with guppies and have been taking back a load of 30 per month to the pet store. We have no good method of counting due to their excessive breeding. overpopulated. We just cannot keep up with the growth of the Pleco and the over breeding of the guppies. My estimate is that we have 50+ fish.

We have roughly 12 Tetras with 6 being new last week (bought while giving back 30 guppies). 3-4 of the new ones are showing white raised spots all over the tails and fins.

I put in Quick Cure with the amount specified for the tetras.  My concern is having the filters off for an extended period of time - I think this might kill the fish....Should I just keep the filters off and do water changes?  


I usually change 20% of the water each month.




-----Answer-----
Hi Ed;

The water changes are a good idea but the filters should be kept on. Just remove the carbon from them so it doesn't remove the medicine.

Keep using the medicine for a full 10 days no matter what the directions say. Quick Cure is about the best one available but it cannot do the job in the three days the label states. Also raise the water temperature to 82f and add aquarium salt. The ick parasite hates heat and hates salt. It will be weakened and the medicine can kill it more effectively. The salt is not harmful to your types of fish for this relatively short-term treatment.

I usually recommend making 25% water changes weekly in all tanks but I'm almost afraid to say that about your tank! You might end up with so many guppies they would take over your house! Fresh clean water weekly induces them to breed and grow even faster. Yikes! If you cut back on food more babies would "disappear" though. Even the pleco will eat them if there isn't an abundance of food added to the tank. It's a natural part of the fish world. Big fish eats little fish. Anyway, it's something to consider...

At Your Service;
Chris Robbins

Answer
Hi Ed;

It's only going to be elevated for a few days so it really isn't a problem for the danios. If the temperature were elevated on a long-term basis it would not be healthy for them.

Don't worry about removing the carbon from the filter. It isn't really a necessary part of your filter and doesn't actually remove ammonia. What actually consumes ammonia is the beneficial bacteria that clings to the carbon and other surfaces in the filter, aquarium gravel and on the inside of the tank itself. Carbon will absorb impurities such as odors, abnormal color, old medication, copper, etc. However, once it has been in use for 5 to 7 days it is no longer able to do that. The little tiny micro-pores that absorb stuff are filled up by then. The carbon then becomes a place for beneficial bacteria to grow so it still serves a purpose, just not for impurities anymore.


I have been concerned about leaving old carbon in my filters since I read that it may release some impurities back out into the water. I only use carbon when there is a temporary water problem and then only for a week or so. I replace it with other filter media that is more permanent such as foam, bio-balls, ceramic beads, etc. If it is a filter pad with carbon sandwiched between fiber, I cut open a spot and shake the old carbon out. I rinse the pad a bit in some tank water and put it back. This preserves the beneficial bacteria but rinses away the crud that keeps water from flowing freely.

At Your Service;
Chris Robbins