Fish tank gravel....

[missann]

I was looking for something to use as a drainage layer in my terrarium where I came across some pretty blue fish tank gravel....thinking of using it in a pot...

Has anyone here used small gravel like fish tank rocks for a potting medium???

I am not afraid of it being too heavy and breaking the roots, because I once had a den. potted in quarter sized chunks of some kind of heavy, gray rocks, and it was not too hard on the plant to repot it.

[kmarch]

I currently have 2 cattleyas potted in pea gravel, not too different form aquarium gravel. I am running a little experiment to see how long it can go without being repotted. So far at least 2 years and counting.

[Hummer344]

Some fish tank gravel is colored. Does the coloring represent a hazard to the plant if it degrades? I don't know the answer to that. I would use pea gravel my self.

[NancyG]

I would second hummer. I think the dye in the gravel might not be good for your orchid.

NancyG

[Andrew]

Originally Posted by NancyG

I would second hummer. I think the dye in the gravel might not be good for your orchid.

NancyG

I don't know to what extent the dyes leach from coloured gravel but fish tend to be quite sensitive to even mild toxic substances in their water. Now I'm not a fan of coloured gravel but it is used extensively in aquariums without noticeable detriment to fish or aquatic plants. Given the long history of spraying, watering or potting up orchids with God knows what whether or not they need it, I'd be surprised if there were any problems with toxicity.

[missann]

Yes, I was thinking that if the sensitive fish are ok with it, then it would be safe for orchids.
Ohhh...also thinking about using fish water de chlorinator in my orchid watering water....

[katrina]

Hi Missann!

I've been raising...even breeding...fish (cichlid family) for years. And, I agree that colored aquarium gravels should be perfectly fine for your orchids. Fish are extremely sensitive to toxins in the water (even sprayed around the tank) and if there was a leeching problem w/those dyes...many fish would die.

As for the dechlorinator...I would avoid using it in my orchid water. One of the main reasons is because many of them should not be used and/or should be used in very sparingly amounts in "planted" tanks. I'm not a chemist so I'm not real clear on the "hows" of this but...it's got something to do with the high levels of phospates in the products (used to buffer the water) -- apparently it locks up CO2 and makes it unavailable for plants. Now...I'm not sure how much that would affect orchids from a root standpoint but I personally wouldn't want to take the chance. The other reason is because the conditioners contain a lot of different chemical ingredients...phosphates, sodium based ingredients, buffers, etc, etc,....all things great for a fish and it's environment but of no real value to an orchid. Quite possibly harmful to the orchid.

If you're concerned about the 'stuff' that's in your tap water...I would recommend using distilled water...there's zero risk to the plants (they like it better than tap water anyway) AND it's a heck of a lot cheaper than aquarium water conditioners.

Hope this help.

[katrina]

Should have added this...I'm not sure how much rainfall you get and/or how many orchids you need to water but...you could consider collecting rain water and using it whenever possible.

I've heard mixed emotions on this topic but I've been doing it for years for my tropical houseplants....long before I was growing orchids. When I started growing orchids...naturally, they got the same treatment and everyone seems to be real happy after a good drink of rain water.

[missann]

It has already rained this year, and I neglected to keep any of the water. I suppose I could just let the water sit for a day or two in order to get let the chlorine evaporate or whatever it does. I'm glad you told me about the part where it says not to use in planted tanks.
I think I read about peroxide being able to get the chlorine out.
Thanks for all your help.

[jbigio]

something to thik about

[katrina]

Hey Missann -- you're welcome. Yep, if you're water is really high in chlorine...letting it sit for a couple/few days will allow the chlorine to evaporate (or whatever) out. That's what some people do w/their aquariums before water changes.