I have just placed three glass vases into my tank cause I haven't found any ornaments I like. I did have these vases filled with gravel and plants planted in the top of them ( one is about 15cm high, the other 25cm, the third is a circular bulb with a hole in the side that I thought would be fun for them to swim into) but after reading koko's dropsy and hollow ornaments thread, I removed the gravel from inside and they're facing up empty.

Is this going to give me a lot of probs. Should I just bit the bullet and get a pirate ship. I was trying to be all art deco but I don't want to hurt my fish

i would say the water would become stagnate. it is a very good idea though, very interesting. if I could make a little change in ideas you may still be able to do your art deco theme. instead of vases, use like the candle vases. I know what im talking about hahaha. umm...they look like vases that you put over a candle or a kereosene lamp, but are open at the bottom and top. if you could place that in the tank and have an air stone in the bottom that may cause enough movement. anyone else think this may cause enough circulation? can you post pics of the tank? I think what you have is an awesome idea and i, for one, would like to see what it look like

a vase with gravel in it is just asking for trouble. it will stagnate and once the oxygens gone from the bottom of the vase, youll get anaerobic bacteria that may convert nitrates into nitogen but, itll let off sulfuric gas as a byproduct. the sulfuric gas is very poisonous to goldies because it can precipitate in their gills.

a vase without gravel in it isnt a bad thing, itll just collect poop in the bottom of it.

as far as the idea for using the oil lamp glass sleeve, that might be a good idea. with gravel in it and an aerator ran underneath it, youd be creating a kind of undergravel type filter that looks pretty neat. the bubbles would pull water up through the gravel in the sleeve and cause a colonization of beneficial bacteria on the gravel. anyway, it sounds good in theory but, is it maintenence freindly?

hope this helps