I'm learning so much on this site. Now that I know about the 10xs rule, I'm wondering if a 250 gph filter is sufficient for a 29 gallon tank. Is the 10Xs rule a bare minimum rule or is it a general rule of thumb.

I have 2 fantails in the tank (6" and 3") and don't plan on adding anymore. Will I be ok with my Eclipse 3 250 gph filter or should I add another small one?

In general - for the rule is just that, a general rule of thumb, you should try to have at least a 10 times turnover of your water every hour. The majority of your beneficial bacteria resides in the filter. You need to pass the water containing the ammonia and nitrites past this bacterial platform in order for the bacteria to process it. The more contact the water has with the bacteria, the more waste the bacteria can potentially process.

If you have a heavily overstocked tank, producing lots of waste, you need to build a platform that contains an extremely large amount of bacteria, and then up the flow of through the filter to allow the bacteria to have a chance to process waste. If you have less waste from fewer fish, a smaller biological population and/or a smaller water flow can suffice.

I have found that the Eclipse tanks are a little underfiltered - at least mine tend to slow dramatically when even slightly gunky. I also do not like relying entirely on the bio-wheel for bacterial base. It most likely is sufficiant, but I like more.

Since an Eclipse is such a nice, contained system, adding another filter to the back can be unsightly. IF you really do not want to go this way, you most likely will be fine with the gph that you have now - particularly if you are not seeing hazy or dirty water at this time. (If you were - you would need more gph).

You could add a small, in tank filter if you wished - but it takes away water volume - something I am always loathe to do.

I would suggest, however, that you add a baggie of biomedia of your choice on top of the blue filter cartridge. The water will flow over it, through the blue filter cartridge and out over the biowheel. This added platform can really go a long way to help process excess waste in a tank. With a solid biological platform and clean filter, you should be ok.

Sounds like a nice setup!

So what does everyone think of this. I went to Drs. Foster and Smith website and asked my "10X rule"question to one of their live chat customer service people and she said the general rule of thumb is 3-5 times your tank volume. When I asked even for goldfish? They produce a lot of waste. She said I could to a little more-- maybe 7-8 times but the 250gph Eclipse would be too big for my tank.

HELP!!!!!

That is written from the standpoint of an expert in tropical or salt water fish, not goldfish. You are right - goldfish produce a tremendous amount of waste - far more than anyone who does not keep goldfish could ever imagine.

The 2-3 or 7-8 times an hour would be a lot of filtration for a standard tank of guppies or other tropicals. But for goldfish, 7-8 times an hour turnover is a little under filtered. If the tank's shape makes for pockets of "still" water, the tank is fully or over stocked, the fish are very large, you overfeed at all, or the filter gets gunked up even the slightest bit and slows, you will have problems. This is the reason for 10X per hour rule of thumb for goldies. I aim for 12 -15 times in all my tanks. Tanks with particularly large fish, tanks with a full load of fish or fish with special needs I go higher.

I have a corner 56 bowfront tank that is biddy to filter. I have an Eheim 2028 (I think that is the number) that does about 256gph supposedly. I added two Emperor 280's to the tank for a total of a little over 800 gph filtration. The tank is now clear. With anything less, it was hazy and ugly. I would add more, but there is only so much side room in the tank's shape. Some very long tanks really need multiple filters - one at each end to properly circulate and filter the water. Some tanks, being deep, need multiple filters set at different levels in the tank - to pull water from multiple places. Some tanks benefit from stategically placed bubble bars or stones to lift the water and circulate it, helping the filters move water. There are lots of options.

But, no, you cannot go wrong by adding more filtration to your tank. You can, in some highly filtered tanks, create a tank that has so much water current that the fish sit at the bottom miserably. The solution to this is to redirect the current, break the current with stones and decorations or cut back on circulation, but this is the extreme. It is easy to have a soft plant that provides an area of calm, or a large stone the redirects the current around an area so the fish stay happy. As long as a fish has a "sweet spot" to sleep in, they generally love the circulation and will benefit from it. The cycling bacteria, too, will grow strong and robust with a steady supply of ammonia and nitrite and oxygen to feed upon.

A 250gph filter for a 29 gallon tank is adequate - particularly with 2 fish. With careful attention, it will suffice. If you add more fish, loose gph from mulm, your fish grow substantially, or have any parasitic or health problems, more filtration could possibly help.

Filtration is a good thing. It is the water's best friend and hense, the fishes.