what size heater are you using? Could be that your present one needs replacement? Or that it's not strong enough to maintain the heat. What type of fish? Some fish are more sensitive to temp fluctuations than others.

You should have 3 to 5 watts per gallon of water....

Since your aquarium is 29 gallons.....it will cool slower overnight than say a 6 gallon. As long as the cooling process is slow.....your fish will be fine. They can take slight "normal" fluctuations without causing them stress or harm. Even with a heater there will be some fluctuation of temp in your tank.

If your heater is to small or can't keep up.....its probably time to replace it. I often us two heaters in larger tanks just incase one quits or something then the other one will at least keep the tank from getting really cold......by this I mean instead of using a 100 watt heater I will use 2 50 watt heaters.

Sierra

29 gallons needs a minimum 150 watt heater. If your heater came as part of a kit and/or you don't know what wattage it is you can check to see if it is marked anywhere on the heater. If not sometimes the brand and size in inches can help determine it. The idea of 2 heaters is an excellent suggestion. Another thing that helps is if it is the fully submersible kind center it under your filter return,horizontaly, close to the bottom about an inch off the substrate. This will help circulate the water located around your heater. Putting it low also helps keep the tank somewhat even as heat rises. If you have a plastic hood light combo you can replace it with a tight fitting all glass canopy. This will help heat from escaping. The new ones have a plastic strip along the back so you can trin away space needed for accessories. The temp. fluctuation is probably gradual and shouldn't be a big deal. Fish in the wild have fluctuations with night and day also.

Kinda embarassed here guys - you are all technical on me and the problem was a nearby window open a little bit. hee hee. Also I guess it's that time of year I'm gonna have to keep the furnace on. Room temperature was getting pretty cold at night. I wasn't really concerned about the quality of my heater, just how much temp fluctuation is ok for the fish.

The heater is 100W and came with the aquarium. The hood did have a breakaway strip with little sections - I thought this was a great idea. Just cut out what I needed.

Skygee, I have a school of serpae tetras, pristella tetras, 2 columbian sharks, a pleco, a pepper cory, 2 gold gourmais and a few misc. guppies and things. Nothing really wild and crazy.

Plan on getting a larger aquarium in the future?

No I just got this one less than a year ago. Do you think I need a larger one?

Gold gouramis get about 5" each I think. Pleco depends, dwarf's 4-6", others 12"-18". Columbian Sharks 12" - 24" Both plecos and columbian sharks can grow up to 6+ inches in a year. You may need a lake. Look up your fish and their needs. Note the Columbian is a brakish water fish, alot of brakish water fish are kept as fresh and will do OK, but they like a little salinity.

Here is a link that might be useful: Fish profiles

I am prepared for the fact that my columbians might need to go to a bigger home soon. I just wondered why you mentioned the bigger tank. Not that I disagree. I plan to get another tank at some point, if only to keep some tiny tetras and rasboras I would like to get but they are just snacks for the bigger fish. But not likely a much bigger tank since I would have nowhere to put it.

My pleco is a common one has grown at least 2" and maybe 3" in 6 months. Again, if it comes to it I will give it to the fish store (they take back huge plecos) and get a new small one. This is one fish I would not want to be without.

I have indeed looked up all my fish and their needs. Unfortunately in the case of the sharks, they were the first thing I bought and I researched them later. I did know that they get big, but now HOW big, and really I thought 29 gal. was a big tank. I have been exercising self control not to overstock my tank. I think 29 gal. is ok for 2 gouramis even if they get bigger.

IC, I have seen Columbians at some stores before. The label sometimes reads "grow to 5"+ , like a pinch of salt in the water". I like the big gouramis, haven't had them in a while. I had the "kissing" ones. They would come up and nip at your finger. You can try a bristlenose/bushynose pleco next, maybe. They only grow to about 4". That way you don't have to get rid of it.

Hi ya NS,

Woe is right here.......You have fish in your 29 gallon tank that get huge and well quite frankly I don't think some of them should even be in the trade. You WOULD need a huge tank or a lake..LOL! I'm not convinced you could actually buy a lake hahahaha...but you can make a man made one....errrrrr woman made one....Na to much work...but we will lend you our gardening shovels if you want..LOL!!!

In all seriousness...if you want gouramis, the best thing to do is just have the gouramis in the tank by themselves.....You have two and if they were in your 29 gallon by themselves...they would grow and be happy. Those sharks that you have are awful beasties.....and they will eat your other fishes...guppies and what have you. I agree with Woe....if you want a pleco for cleaning algae in your tank....get a bushynose.....they will act pretty much the same and will only get 6 to 8 inches. Peckoltia is another option for you....again they stay small. Corys are very social little catfish and should be kept in groups of 6 or more....the larger the group the happier they are. But to me...is sad to just keep one. Serpae tetras are nasty little buggers...they are fin nippers and should not be in a community with guppies or a betta or anything with long fins....or fins for that matter. When I kept and bred them....they were in a tank all by themselves. I am not sure what a pristella tetra is......so not sure about their behaviour.....but tetras are schooling fish and should be kept in schools of at least 6 and more if possible. I love rasboras......I had a dedicated community for rasboras....they are a very interesting fish to observe....again you will see more natural behaviour with larger schools.

You say you have nothing wild and crazy....but well....ya kinda do. Sorry but don't you want healthy happy pets?

I am also curious....what size of tank are your goldfish in?

We really arn't trying to pick on you here...just trying to help you with what is reasonable fish for your 29 gallon community tank. All fish are NOT compatible....and as I mentioned above some of those larger fish..IMO shouldn't even be available in pet stores. Oh and on a cautionary note.....not all tetras and rasboras will be compatible either.

Oh ....and if you have room for one more small tank...I would recommend a quarantine/hospital tank. This is very important when adding new fish to a community tank or for treating a sick fish...without having to treat the whole community. You will find this will save you $$$ in the end.

Sierra

P.S. Oh ya....and I highly recommend that you close the window. LOL.

Ok ok the window is closed. LOL. I am starting work on my lake - what wattage of heater do I need? haha

Seriously though, I certainly don't feel picked on but sometimes it seems like NOTHING should be kept with ANYTHING else. And the same fishes must behave differently for different people.... for starters, my serpaes are fast swimmers and like sorting out their serpae pecking order, but they utterly ignore the other fish. I have been observing them closely especially since they have grown quite a lot since I bought them. There are 5.

Pristellas are also called X-Ray tetras, they are pretty, slim, medium sized tetras and very peaceful. They are silver with yellow/black/white fins and a reddish tail. They don't school strongly but mill around together a bit. I have 6.

Nothing in my tank has long fins. My betta is a handsome short-finned male - it was actually sold to me out of a tank of females as a female. Musta been one lucky betta - it would be like the playboy mansion. haha. I found a pic that looks just like it on a fish website. You can tell the difference between nipped or rotten fins and these short fins, they have a scalloped edge. Plus it is bright blue and red and has no stripes. I didn't know these existed until I bought one by accident.

Sierra, sorry you think my cory cat would be lonely - it has never seemed so to me. Always looks happy skipping around the bottom.

Oh yeah and it WAS the columbians eating all my neons, I caught one chasing the last one around. Poor things. I need to find a happy new home for these guys before they get big enough mouths to snork up the bigger tetras. I will get it sorted out eventually -sigh.

Oh yes and BTW I also love rasboras. If I get the "no eating each other allowed" tank going I would like to get some Hengel's rasboras - I had these before and they are gorgeous. But so tiny! They have a little orange "Nike swoop" on their side.

Here is a link that might be useful: {{gwi:379664}}