Your site is very informative and very, very, very helpful. I am new to this owning fish business. Right now I have 2 large comet goldfish, 2 small comet goldfish and 6 Koi, approx. 4.5 inches long. I am keeping them for now in a 100 gallon tank outside with 80 gallons of water in it (down so they don't jump out).

I need to know how to make a home made Bio-Filter. Right now, all I have is a submersible pump with small filter on it, (filter is only two inches by 2 inches) that pumps the water from bottom of tank and back in a water fall at the top. 210 GPH pumped.

I give them a limited amount of three choices of goldfish food twice a day. I also clean the small filter daily and change 20% of the water daily. I also am adding 1.5 tablespoons of aquarium salt per 16 gallons of water changed daily although the carton says to use 3 tablespoons per 15 gallons. Salt is "Evaporated Sea Water", manufactured by "Aquarium Pharmaceuticals Inc". I also have 1/2 of tank covered for shade from hot sun. I keep reading about adding so much more salt? A lot more salt?

(1) Is it okay to change 20% of the water per day? They seem more happy since doing it and it is keeping the Algae under kind of control without using chemicals? Key words are KIND OF................

(2) Is it okay to use a minimal amount of aquarium salt all the time? I have been through Ich and Cotton disease before using it? Again they seem healthier now that I am using it?

(3) Could you tell me how to make a Bio-Filter cheaply?

(4) I live in northern Alberta, Canada. If I bring them in for the winter, they would be at house temperature, do I continue to feed them the same amount?

(5) If I placed them in an above ground 300 gallon tank and used floating tank heater (for livestock), would they be better off than in the house but cut back on feeding? And if cut back on feeding, by how much? They would not have any filter system if outside in the winter as the water fall would freeze?

(6) Does salt control fish parasites, worms, flukes, etc.? If not, do I treat them a couple of times a year for such parasites as they came from a Pet Store where other people say the fish come with such problems?

(7) I printed out any of your Questions and Answers pertaining to me. Two things that scare me. Question 19 states 1 inch of KOI per 20 to 25 gallons??? I understood when they were still small, it was 1 inch of fish per 1 gallon? Second was a Q and A that says Goldfish are okay wintering in an Aquarium but Koi shouldn't be??? They should be in a tub??? I really wanted to be able to enjoy them in an aquarium for the winter??? I thought a 77 gallon to a 90 gallon for this winter and hopefully the next. In the spring, I would relocate them to a 300 gallon horse tank???

Thankyou for such a good site. I have been getting all this conflicting information from looking at other Koi website pages so am hoping you can help clear up my questions? Thankyou kindly, Gayle

1) Water changes: Given the current volume of your container, 20% changes on a daily basis are all that is keeping your fish alive. Since you have NO biofiltration and an overcrowded pond, 25-30% would be better. Remember to treat for chlorine and chloramine, and replace salt.

2) Constant levels of salt are a good thing, reducing metabolic stress on the fish and acting as a mild anti-parasitic. It also protects your fish from Nitrite poisoning, which will be an issue once you build your El Cheapo biofilter. Using aquarium salt will bankrupt you. Solar Salt crystals from Menard's (99.7% pure salt in the blue plastic 50 pound bag), normally used to recharge water softeners, costs about $3 a bag and work just fine. A level of 1 1/2 pounds per 100 gallons is good for the fish and won't kill the plants. Remember to replace what you lose with your water changes. Buy a good salt testing kit to monitor your levels.

3) The best and easiest biofilter I ever built was put together thusly: Buy a big, sturdy plastic garbage can, a length of 4-inch PVC pipe about 8 inches longer than the can is tall, and some 1 1/2 inch PVC pipe with elbows and connectors. You will also need three knife valves and three bulkhead fittings, a sheet of plastic grating, and a polishing mat (new) for a rotary floor polisher. Try to get one the same diameter as the top of your can.

Start by cutting holes in your can, one very close to the bottom for a sump drain, one right up close to the top for a water feed, and one about six inches from the top for your outlet back to the pond to fit your bulkhead fittings. Install your bulkheads and screw them down tight. The fittings are threaded and will fit standard PVC fittings. Your Home Depot guy will be able to help you here. Any threaded fittings need to be sealed with Teflon tape, and PVC joins need to be glued with PVC primer and cement.

Cut 2 or 3-inch tabs out all around one end of that 4 inch pipe. This end will go down into the bottom of your can, right in the center. Place a couple of small bricks or largeish rocks on the bottom of the can around the inside edges to support the grating above the lowest bulkhead. Cut your grating to fit over the pipe and into the bottom of the can. It does not have to be perfect. Push the grating to the bottom of the can so it rests on the rocks. It'll help keep the pipe in place, too.

To the topmost bulkhead, on the inside of the can, attach an upside-down "L" shaped pipe that you have made out of PVC pipe and 90-degree elbows. The feed from your pump will fit into the outside end of this bulkhead, and the water should pour out of the "L" and splash into the 4 inch pipe with a lot of turbulence at the bottom. The "L" should be able to swing away from the 4-inch pipe to allow for cleaning. You will also want a valve (I like knife valves) on the long arm of the "L" to control flow and act as a shutoff for cleaning.

The middle bulkhead will attach on the outside of the can to a pipe to your falls. You will want to situate the filter well above and fairly close to your falls so that gravity will alow for a rapid flow across your falls. You will want a valve here, too. Keep the outflow pipe as straight as possible to minimize resistance to flow, and hide the pipe under rocks and plants. Bare PVC is *ugly*!

To the outside of the bottom fitting, attach another valve, and then a pipe to wherever you want waste water to drain. Remember, you can't use pond water with salt in it to water your garden! It'll kill your plants.

Fill the can with filter media. This can be anything, but I prefer PVC tape, because it never fouls and is super light and easy to clean. It is sold as "BioFil" from either Whitewater filters in Batavia, IL, or Aquatic Eco-Systems in Florida(www.aquaticeco.com). Failing that, filling the can to just below the outlet with plastic scrubbing pads from your local flea market works as well. So does the plastic strapping used to make cheap lawn chairs. Try to stay away from pea gravel and "lava rock". They are heavy, foul quickly, and a (bleep) to clean.

Finally, cut your polishing pad to fit your 4-inch pipe in the center and the can just below the outlet, swing the "L" away from the top of the 4-inch pipe (the bulkhead will act as a pivot), and push the pad into the can so it sits on top of your media just below the outlet bulkhead.

Cut a hole in the can lid to fit over your 4-inch pipe and the "L", and put it on.

Hook up your pump, pretreat your pond with a healthy slug of bacteria booster, and let 'er rip! It will take about a week to ten days for the Ammonia-to-nitrite reaction to kick in (good salt levels are a must here!) and another ten days for the nitrite-to nitrate to show up. You might want to buy an inexpensive UV unit to plug in after the filter, because algae *loves* nitrates.

Once a week, while the filter is running, open the bottom sump drain to flush out the sludge. When the mat looks ooky, pull it out and rinse it in pond water. The media can be shaken up at this time, and back-rinsed with pond water directly from your pond pump. DO NOT RINSE ANY PART OF YOUR FILTER WITH TAP WATER! The chlorine and chloramines will kill off your bacteria and you will have to start all over.

4,5,7) Koi will need to be fed very lightly when brought indoors. Keep the water around 60-70 degrees. (Don't put a heater in!) This is mostly because there is not an aquarium filter made that can keep up with a koi, even a small one! Make up a smaller version of your garbage can filter and use the media from your outdoor filter to stock it. Better yet, get a 300 gallon horse trough from your local farm supply place, stash it in your basement and drag the outside filter inside and keep it running! I am dead serious about the water volume requirements for koi. They are very wasteful fish, in every sense of the term (pun intended!).

7) Salt is good, but not perfect. Higher concentrations (2.5 pounds per 100 gallons) are needed, and many parasites develop a tolerance to it. Proform-C, Dimulin and other agents are available from vetrinarians for definitive antiparasite treatments. Usually, repeated treatments are not needed unless new arrivals bring unwanted guests.

PLEASE read all the info we post on quarantine and safety procedures! It's all real, and all necessary!

Bob Passovoy
President
MPKS