[Agrippa]

Well, I know that there have been a lot of threads lately about simple sand substrates, but I have an issue that I have yet to read about... So, I bought basic playsand from Home Depot and rinsed it using a paint strainer, and have used it in 5 tanks. In the first and third tank I used it in, it worked great, and stayed an aesthetically pleasing tan colour; however, with all of the others, it began smelling rather foul, turned grey, and started killing plants all within a few weeks after being put in the tank. I'm assuming it's bacteria, as the smell is somewhat sulfuric, but I can't tell why it worked in the other tanks... So, any ideas? I'm at a complete loss here...

 

[Rex Grigg]

Is the sand the same sized grains? Many times sand sold as play sand in parts of the US is much to fine to use in an aquarium without having the problems you are. If you go to my Guide there is a picture in the Substrate section of the minimum grain size you should look for.

 

[Agrippa]

...Wow... That was rather obvious... Yeah, I just went to look at the sand in my two functioning tanks, and saw that they were very similar to the picture in your guide, while the others were aconsiderably finer, even though I used the same substrate and strainer... I guess I just did a better job of separating it in the other two... So, basically, the sand just compacted and squished the roots of the poor plants and helped cultivate anaerobic bacteria. Well, thanks for helping.

 

[Rex Grigg]

No problem.