Is there room?

[Jakaris]

I have a 26 gallon tank with 1 Angelfish, 2 Pink Kissers, 6 Harlequin Rasboras, 2 Flame Tetras, and 4 corydoras (not exactly a space hog.... http://www.aquaticcommunity.com/aquariumforum/showthread.php?p=16441#post16441),
My question is can i fill out the Flame Tetras into a small school, maybe 5-6? THeir survivors btw, I didnt just grab 2 because they looked nice.

[Fishguy2727]

What filtration do you have? What is your water change schedule?

[Jakaris]

I have a Penguin Biowheel 150, made for 30 gallon tanks, so slightly over-filtered, and i do water changes of 25% every 4-5 days, and i have to add water ever y 2-3 days because of evaporation (dry winter here).

[Fishguy2727]

Whatever a filter claims it can handle, you need to cut that in half. So you need filtration rated for at least twice the actual volume of the tank. So before spending money on more fish, I would add more filtration. When you do add gish, make sure you total at least 6 for each schooling species (the flame tetras, rasboras, and the cories). Harlequin rasboras do best when in big schools of 10-12.

[Jakaris]

You sure? The water current seems almost too quick as it is.

[Fishguy2727]

It should not be an issue. My 40high has a Fluval 405 and a Whisper 60. With adequate decorations the current should quickly be disipated. With hang on backs the current is usually disipated onto the front of the tank. It may be strong right at the output, but through most of the tank it should be a lot lower.

[kimmers318]

It seems to me that even with overfiltration you are close to being maxed stock....the saving grace is that the cories stick to the bottom and the others probably hang higher, which in my opinion defintely helps when stocking to the limits....this way the fish aren't fighting for space among themselves. My biggest concern would be that angels get rather large don't they....and are also pretty territorial. Is yours full grown and laid back....or is there a possibility that when it is all grown up he/she might get a little cranky sharing space? A good way to tell in my experience if your filter is handling the load you have well is to check water parameters frequently...maybe every other day, for a few weeks. See if 1) you are getting any ammonia or nitrite reads and 2) how long it takes for your nitrates to build up. If all is staying well you might try getting away with just adding 2 fish for now....and then watch again to see if things stay stable. I know ALOT of people go with the double filtration method, but I have a 30 gal that came with it's own filter, I am pretty sure the manufacturer included a filter for the tank volume, not something double....and it is always fine.....same with my 5 gal....it is overstocked slightly, but all stays well, the cories stay on the bottom, the betta on top. My 10 gal dp tank came with a filter for 10-15 gal tanks....and although dps are small, they are carnivores which generally leads one to believe messy tank....never an issue there either. Hubby's 90 gal has a magnum rated for 100 gal tanks....all is well there with 2 oscars and a HUGE pleco. Only my 20 gal tank has 2 filters running to keep it crystal....one rated for 10 gal, one for 20 gal.....the difference in my opinion is that neither of those filters has a biowheel....whereas the others all do. My next big purchase after the holidays will be a biowheel filter system for that tank.

[Jakaris]

Yeah, I love my biowheel, i had one before with no biowheel and it was always ALMOST clear..... but yeah, I've been doing readings, and i have absolutelly no ammonia, and very low levels of nitrates/nitrites. I havn't seen a spike in a week, so its pretty stable. And the angel is semi-small right now, but I have a tallish tank (about 20 inches I believe), and the kissers decidedto pick the top of the water as their terrotory... along with one lone rasbora who likes to "ride" the filter output :D

[cubanitoloko23]

i don t know that i would put any more stress on the bioload, and think about it, tall tanks have a smaller surface area so less gass is exchanged meaning less fish you can keep.About fitration, you can never be underfiltered and usually what the filter claims to do is not accurate, increase the filtration. If you do increase bioload then check your water constantly and remember to do weekly partial water changes.

[Jakaris]

I said somewhat-tall, not tall. Heres a pic: http://i6.photobucket.com/albums/y215/Jakaris/11270007.jpg

[Fishguy2727]

I have not found surface area to be as important as it used to be. With moderate surface agitation you can completely negate the effect of low surface area because more water is passing by the surface, and it does not take long for oxygen and carbon dioxide to cross that air-water boundary. This is especially true of biowheel filters where there is a tremendous amount of oxygenation taking place. If you have adequate filtration (filters rated for up to at least twice the actual volume) you should not have an issue with oxygenation, and if you do the fish will let you know.

[jeffs99dime]

i am a firm believer that you cannot over filtrate. the more the better is what i think. you can have too much current however. you just have to find a happy medium between the two.