how big do BN plecos get, read description?

Thanks for asking around before you bought one. :)

Bristlenose plecos (Ancistrus species) should fit well into 125 L/ 33-gallon your aquarium. I have had a trio (M,F,F) spawn a number of times (that rascal spawned both females after one storm front ran through) in a 29-gallon/ 110 L aquarium. There were some pretty robust predators there & fry couldn't grow up in there until I removed the red-tailed Goodieds & the large rainbowfish. (I wanted baby bristlenoses & really didn't want those others dining on baby Ancistrus. They spawned in a chemical free flower pot, a really ugly ceramic cave (garage sale special) & eventually just in tank corners.

Our largest males grew to about 15 cm / 6 inches. A very good sized female runs about half that size, but they may be smaller.

About six years ago I purchased a bag of the gold/albino common bristlenoses. (There are a lot of species.) I put them in a 20-gallon/ 76 L to grow out. There were inert rocks placed on the on the tank bottom, not on the gravel. They will try to burrow under the rocks & can get crushed. There was a small power filter & a lot of floating plants.

A pair formed & eventually I removed all of the others. Don't keep two males in a crowded tank. In fact don't buy two separate males & put them into one tank... soon you will have one. Still the old stud tolerated his sons and in time I removed two pairs to other tanks & sold another 6 pairs or trios to others in aquarium clubs.

I am pleased to see that another correspondent has two males comfortably ensconced in a 55 gallon tank. That must afford them territories of their own.

One of the reasons they spawned so readily is that I was really taken by them & actually did my 50% weekly partial water changes with treated water of the same temperature. 50% of the water & a lot of fecal material was removed by gravel vacuuming. It was also left overnight in a food quality barrel with a heater to shed noxious gases & to absorb some free oxygen.

I also never cleaned the filter floss so that it was light colored, thereby keeping a lot of the beneficial bacteria. The big pieces were washed out.

If your municipal water source is ultimately a river, lake or reservoir, you should have no trouble with them not spawning because there is too much mineral in the water. I have to cut or remake our liquid rock from wells (445-775 parts per million TDS or total dissolved solids), Diluting is done gradually with RO (reverse osmosis) water, but could be done with clean rainwater (collected more than 30 minutes after it begins pouring) or the more expensive distilled water. Once the appropriate TDS is met, changing water is mixed accordingly ahead of time in a 32-gallon Rubbermaid trash can dedicated to all things fishy.

Bristlenoses will scavenge flakes not eaten by other fish & that is probably beneficial all around. However they are mostly vegetarian and will even chew on a piece of driftwood! (It will never have algae on it!) They thrive upon algae tablets & the occasional slice of blanched (or 1 minute in the microwave) slice of zucchini (or other squash or cucumber) or a couple green beans. They love the insides of cooked peas.

That diet will prepare them to spawn. And they should leave the plants alone. ;)

Your tank is under planted, but the light loving plants will require 3+ watts per gallon. Put a light timer on that light & try 10 hours/ day. If the plants don't stay vibrant, extend the time they are on. (& change fluorescent bulbs every 6-12 months, they gradually lose intensity.)

For some easy to grow, fairly inexpensive plants please see:

http://answers.yahoo.com/question/index?qid=201307...

For more on breeding them and sorting the mustachioed males & "clean shaven" females please check out":

http://answers.yahoo.com/question/index;_ylt=Ahvfn...

In time I have added young livebearers & young Fundulopanchax gardneri to those tank because I needed space for promising youngsters. The guppies & bristlenoses left each other alone. To my pleased surprise there are a lot of gardneri eggs that escape the catfish's attention & I keep snatching pairs of gardneri for club meetings.

One of the neatest aquariums I have ever seen was a friend's 55-gallon/ 208 L with lots of structure on the tank bottom & a superior strain of guppies. There were baby & young bristlenoses all over the place. It was quite a show!

If you can, snag a bag of bristlenoses from an aquarium club auction (Google aquarium societies & your district). Shop stock is usually fine too. If you know you can move extra bristlenoses to another aquarium of yours or a friend's, consider buying a bag of youngsters. They may be cheaper per fish, will travel well, will adjust to new quarters more easily and will give you a bunch of great algae munchers for a half decade at least!

The biggest bristlenose pleco I've ever seen was about 5 inches long. Most are closer to 4 inches.

Will one fit in a 125-liter (33-gallon) tank? Yes.

Will it eat your live plants? Maybe. If you give it enough food (with plenty of vegetables), it may leave the plants alone.

By BN, I assume bristle nose? I have 2 in my 55 gallon and they are both males, 2 years old. They are about 4 1/2 inches long and have been that way for the past year. Grime what I've researched, that's as big as they will get. They don't eat any of my live plants, but they love the drift wood I have in there for them (bought it at my local "mom & pop" fish store) I usually feed them algae tabs in the morning (one each on each side of the tank, they have learned wher their "food drop" is) and I will usually put a couple slices of room temp cucumbers in there. All the fish love it and it keeps them healthy. I hope this helps

You could have one in that size tank, and they usually won't eat plants. Delicate leaves may be damaged during algae eating, though.

They get to be about 5 inches.