Hey everyone! I know I mentioned this in a previous post, but I'm looking at setting up a "budget" tank at some point down the line, and, well, live rock (and even to some extent dry rock) is not exactly "budget" friendly. So, while I am planning to use some live rock to seed the tank, I'm also looking to see if there are any cheaper alternatives to live/dry rock that won't leach deadly metals into my tank. As a note, the cheapest dry rock options I've found so far are available through BRS and Reef Cleaners, and they run ~$2.50 to ~$3.00 a pound. That's not a bad price, but when you compare that to stuff like lava rock (scoria) which is ~$4.00 for 25 lbs. and was (and to some extant still is) used in the freshwater scene, it looks pretty expensive still.
So, on that note, with "lava rock" (scoria) being so cheap, it looks pretty tempting. However, I have heard many concerns (including from people on the freshwater side of things) that metals may leach from the lava rock into the tank and nuke the livestock. On the flip side of that, I know that some (possibly many) people have used lava rock with no issues, but I understand that some lava rock is fine while other lava rock is not and there's not really anyway to tell which is safe and which is isn't.
So, my questions are these; first, are there any other super cheap rocks that don't run as high of a risk of leaching metals, and if so, what are they? Second, if one were to use a rock, such as lava rock, which does have a fairly high chance of leaching, how long would the rocks need to go through the soak/rinse cycle before they would be safe for livestock? A week? A month? A year? Longer? Third - if you have any recommendations for cheap types of rock - how porous are they compared to your typical live rock, dry rock, or lava rock? (As a note here, I know there is some debate as to whether or not porosity is actually helpful to the filtration process, but I've also heard that porosity is good for microfauna. So - barring any information being put forth that shows porosity is actually detrimental to/not helpful for the microfauna in the tank - I'm hoping to find something that's pretty porous to use).
Thank you!
So, on that note, with "lava rock" (scoria) being so cheap, it looks pretty tempting. However, I have heard many concerns (including from people on the freshwater side of things) that metals may leach from the lava rock into the tank and nuke the livestock. On the flip side of that, I know that some (possibly many) people have used lava rock with no issues, but I understand that some lava rock is fine while other lava rock is not and there's not really anyway to tell which is safe and which is isn't.
So, my questions are these; first, are there any other super cheap rocks that don't run as high of a risk of leaching metals, and if so, what are they? Second, if one were to use a rock, such as lava rock, which does have a fairly high chance of leaching, how long would the rocks need to go through the soak/rinse cycle before they would be safe for livestock? A week? A month? A year? Longer? Third - if you have any recommendations for cheap types of rock - how porous are they compared to your typical live rock, dry rock, or lava rock? (As a note here, I know there is some debate as to whether or not porosity is actually helpful to the filtration process, but I've also heard that porosity is good for microfauna. So - barring any information being put forth that shows porosity is actually detrimental to/not helpful for the microfauna in the tank - I'm hoping to find something that's pretty porous to use).
Thank you!