[Ziggy]

Many years ago I had the regular red Fluorite in my 10Gal low tech and really liked what it did for the plants...but at some point after that any Corys I kept would suffer from disappearing whiskers and at the time there was a prevalent notion on the web that the Fluorite was “sharp” and thus to blame. I covered it with a layer of super fine black gravel (Hagen GeoWhatever), but over time it just blended and the red Fluorite came to the top and it looked stupid more than anything.

Without re-questioning that old notion, I strained out all the Fluorite a couple months ago as part of a tank reboot (it had been almost a year without inhabitants), so I only have very fine gravel. Plants are not doing well. The new leaves on the Jungle Val, although growing 1/2” a day, are anemic. I’m sure its because they are getting nothing from the gravel.

All this to say that I was going to just flip the whole smash (again) for the Fluorite SAND but when I saw a bag today at the LFS two things hit me:

1) it is a LOT finer than I thought it would be. I wonder if anaerobic bacteria (and the infamous poison gas) is going to be an issue.

2) Even though its finer, it is ultimately the same stuff and potentially "sharp" (or whatever), though I don't know if that was ever asserted beyond the anecdotal.

PS I did do a search of the forum before posting so please forgive if this particular angle has been discussed before by the old guard.

 

[Jim Miller]

My corydorus habrosus have had a wonderful 6+ months snuffling around in my flourite black sand and are very healthy. I have my FBS atop a base of MTS and everything is growing very well. No anaerobic issues. No packing. Very easy planting as well.

Jim

 

[ubr0ke]

http://en.aquanet.tv/Video/225-soft-barbels-on-sharp-gravel-surprise-corydoras-live-on-various-substrates
I really don't buy into the whole sharp substrate hurts cories..here's a video you should watch

 

[sampster5000]

There is something about these sand substrates that mess cory's up. I have kept many corydoras for years. I have only had success on plain gravel and aquasoil. When I tried out tahitian moon black sand with my cory's, half of them died (ones I had for several years on gravel) and the other half turned very dark and never moved. They were like this for about a month. I then took the survivors and put them black on plain gravel and within a week they were very active again and had their color come completely back to normal.

 

[AirstoND]

http://en.aquanet.tv/Video/225-soft...surprise-corydoras-live-on-various-substrates
I really don't buy into the whole sharp substrate hurts cories..here's a video you should watch

+2

I have seen no videos of barbels being damaged by gravel. Some cories might be prone to it either due to stress or heritage. Don't they grow back? I know danios have been studied for their ability to regenerate organs.

 

[Ziggy]

..here's a video you should watch

Thanks for the link. Very interesting. Shows us what substrates are in a variety of Cory species' natural habitat... none of which were Fluorite of course. While the notion that Fluorite is harmful to them is still only anecdotal, we cant really say this video proves it isn't, but it does suggest that size and shape of the substrate may not be as critical as people think. On the whole their natural habitat seems to include river beds of varied, though generally smaller, material intermixed with rocks and a fair amount of dead vegetation, but even more interesting to me was the wicked fast current throughout, both points I'm sure are good to know going forward.

I'd have liked to know what those plants at 1m:48s were rooted in.

 

[ubr0ke]

I don't see any plant at 1min 48...

I have had flourite in tanks with cories...no issues with sand or gravel..

I think water quality has more to do with barbel infections then substrates...

 

[Ziggy]

I don't see any plant at 1min 48...

Sorry, make that 3:28.