sw10mm wrote:Well the headline states it all what do you use? Play sand is cheap but messy and I hear fahakas can bury.... pool filter sand is a lil expensive (to fill a. 220 gal tank) but hear it doesn't compact or should I do pebbles or small colored rocks? Was thinking red but 11 bucks for 20 lbs idk.... I havee about hundred dollars and I'm open to suggestions to what will make my fahaka happy and go. od color
I am unsure if this information sufficiently answers your inquiry, so take this for what it is worth.
"Sand" generally is SiO2 unless it is targeted for marine applications.
"Sand" within the domain of use in Reef and Marine fish will hopefully consist primarily of CaCO3.
At this point your decision tree consists of the following considerations:
1) Grain size
2) Grain "smoothness"
3) Targeted aquatic environment
Accepting that play/silicate sand will release Silicates into the water column, and that Aragonite/Coral gravel will affect general alkalinity and PH while reacting with acids thus producing many Calcium and Carbonate compounds as a result of the Calcium<=>Phosphorous cycle, your main objective is then reduced to facilitating the habits of your average puffer.
Given the proclivities of a normal puffer trend towards the interaction of the animal with the substrate for a variety of reasons, my advice is to select a medium which is
both smooth and chemically appropriate to the natrual environment of your friend.
The properties of any given substrate from a minimal packing volume perspective can be deceptive and insidious.
Keep in mind that for any given amount of poop that your puffer will produce, the volume per unit time of water circulation at the column/substrate interface must be sufficient to prevent poop aggregation and the formation of anaerobic zones.
Hydrogen sulfide is not ok, but
will be produced [along with N2] if your substrate is of too small a granular consistency, too great a depth and of a water column/substrate flow exposure time insufficient to facilitate the diffusion of both the undesirable nutrients and the oxygen required to process them.
I am in the process of falling asleep as I write this, but fairly decent research on this subject has been performed in a marine context, though the principals elucidated therein are probative to both your question and the body of my response.
I shall be happy to present an aggregate of links supporting my assertions as time allows this week; I truly practice my belief that one should not blindly accept unfalsifiable claims, and that any advice given with direct or potential critical application be supported by empirical reference to operative theory validated through corollary documented outcome.
....And yes, I do speak as I write, much to the confounded chagrin of my coworkers and subordinates.
I hope my answer clears up any questions you might have had, and not in a "clear as mud" sort of way.
A lot of the references below target a Marine environment, but much of the same logic still applies.
References and Suggested reading [also see my post in the 300g tank thread of mine for more]:
Nutrient Cycles [Beyond the Nitrogen Cycle]
http://www.skepticalaquarist.com/nutrient-cycles
Sandbed calculator
http://reefkeeping.com/index.php/sand-bed-calculator
Phosphorus Cycle
http://www.elmhurst.edu/~chm/vchembook/ ... horus.html
http://en.wikipedia.org/wiki/Phosphorus_cycle
http://www.skepticalaquarist.com/phosphate-cycle
Feature Article: Silica In Reef Aquariums
http://www.advancedaquarist.com/2003/1/aafeature1
Aquarium Chemistry: Nitrate in the Reef Aquarium
http://www.advancedaquarist.com/2003/8/chemistry
Chemistry And The Aquarium: Phosphorus: Algae's Best Friend
http://www.advancedaquarist.com/2002/9/chemistry
Marine Fish Poop -- A Major Calcium Carbonate Mud Source?
http://www.advancedaquarist.com/blog/ma ... mud-source
An Experimental Comparison of Sandbed and Plenum-Based Systems. Part 1: Controlled lab dosing experiments
http://www.advancedaquarist.com/2005/6/aafeature
An Experimental Comparison of Sandbed and Plenum-Based Systems: Part 2: Live Animal Experiments
http://www.advancedaquarist.com/2005/7/aafeature