I need a bit of help with my nitrites. I have a 77 gallon tank with 5 koi and 5 goldfish. I purchased a new filter three weeks ago and was pleased with the results. However my fish seemed to be gulping for air at the top of the tank with in 3 days. I took a sample of water in to the fish store and got it tested. My nitrites were through the roof. They told me to go home and do 2 water changes a day minimum of 25%. I have done that for 5 1/2 days. My nitrites are between .1 and .3 now. My question is should I clean the filtre again or should I leave it alone. I am leaving for holidays in less than a week and want the fish to be healthy before I leave. Should I continue with twice daily water changes or can I go to once daily now???????Thanks for the info.

first off, i must warn you, you are probably very heavily overstocked! how big are these fish? a 77 gallon tank is just right for 5 full grown goldfish.

you say youve got 5 koi in there as well? koi tend to need quite a bit more space than that. each one (full grown) needs 300 gallons or more! i think.

secondly, when you got your new filter, did you use any special precautions to preserve your beneficial bacteria? if not, you probably just took the old filter out and put the new one in. right? if so, your fish are suffering from "new tank syndrome". your tank is probably rebounding as i type this so, peruse over this link and pay close attention to what you can do for your goldies.

http://www.kokosgoldfish.com/Keepinggoldfish.txt

http://www.kokosgoldfish.com/cycle.html

post back soon with anymore questions you may have!

in short, you really need to think about returning the koi. there is just no way around it. they ARE going to need much more space than a 77 gallon tank (or any tank) will ever provide.

once you have done that, your tank and filter will have a much easier time handling the bioload created from 5 goldfish. incidentely, what is the brand and model of your filter?

you will also have to get yourself some test kits. they are essential to fishkeeping, as you can see. you should get those ASAP. then test your water and post back with the results.

you might as well get yourself some aquarium salt while your at the fish store. the addition of aquarium salt (dissolved in a cup of tank water) at 1 tablespoon per 5 gallons will help your goldies to deal with the high nitrite levels. first, add the correct amount of salt for the total gallonage in your tank (15 tablespoons). then, add the corect amount of salt to the amount of water of each of your water changes.

hope this helps

It sounds like your tank is in the middle of a nitrogen cycle. There is little you can do to hasten this process. It needs to take it's course. You can help it along by increasing the oxygen with aeration. Keep the bio-filter and fishes happy with temperature between 70-75F.

Be sure you have adequate carbonate hardness (KH) in the water. Nitrifying bateria uses up this element. If you don't have sufficient carbonate hardness, use a pH buffer or baking soda to prevent a pH crash. Don't change pH more than 0.2 per 24hrs.

Since you are going away shortly, you'll want to change your water just before you leave. Use one of the water conditioners like Amquel + or Prime, available in your local pet store. Add 5 times the regular dose. This will render the toxins like ammonia and nitrites less harmful to your fish and yet not interfere with the cycling of your tank.

One last thing, which is a bit controversal and someone may challenge me on this. Do not feed your fish while you're away. The idea is that; no food no waste. I've read that goldfish can survive up to 2 weeks without food. One time I had forgotten to turn the power on to an automatic feeder. A week plus later when I returned I found the fishes were hungry but perfectly fine.

Hope this will help you with worryfree vacation. B)

Thanks for all the info. Yes I will admit, I did just take out the old filter and put in the new one. The place where I get most of my fish stuff is really good, and I can't imagine why they didn't tell me a safer way to do this. They know I am a relative beginner. The filter system is a Magnum 350 deluxe. I live out of the city by quite a distance, so it will be some time before I can get to town to buy all the kits I need for testing. I purchased the nitrite test kit when I realized what a mess I was in. They told me everything else was alright, so I wasn't concerned about any thing else. I wonder why they would sell koi to me if they needed so much room to move. My largest Koi is 11 inches long and she is less that one year old. It stands to reason she will get a lot bigger. I imagine it will be a good time of the year to find them another home seeing as pond season is coming. I have a pond in the back yard, but it is still below zero here. Needless to say they can't go outside yet. I can find homes for the goldfish, but the end result is the same. There will not be enough room for the Koi. I made arrangements for someone to come into the house every two days to feed the fish. I imagine I should continue with that plan, as I have two other tanks on the go. One with fantails and such, the other is tropical. I think I will just get her to feed the Koi sparingly.

if youve got a pond that is inhabitable during the warmer months, you can winter koi in the house pretty easily. for 5 koi, several 50 gallon storage bins with a dedicated filter for each work very well. the filtration should pump ten times the bins capacity each hour (gallons per hour). aeration is a good addition to have as well. again, the bins should only be utilized during the coldest months of the year (while its snowing). transplanting to the pond should be done as soon as possible and there is a specific way to acclimate them to the difference in water chemistry.

as far as your filtration is concerned, i would run your new one as well as the old one. the reason for this is that your magnum 350 only pumps 350 gallons per hour. if your tank is 75 gallons, that means that your only getting a filtration rate of about 5x an hour. thats just not enough (even for an understocked tank. thats probably the main factor in your tank having such high nitites! a tank of your size with the amount of goldies/koi in it desperately needs a rate of 10 times an hour (or more). go ahead and set the other filter back up for now. i garauntee you that your fish would thank you for it!

toothless