Is npx bioplastics media considered carbon dosing? Also why is carbon dosing bad for a tank with a dsb bed? I am vodka dosing on my 72 gallon right now. It has dsb and I have had no problems.
You
can, but its difficult to get to a balanced state where you lower nutrients but still provide
enough to feed the dsb. The point of a dsb is to have a true BIOfilter where you use a natural means to eliminate nitrate and phosphate. The animals biomass is where the nutrients are stored and converted to less harmful substances. Then the aerobic bacteria convert their wastes to nitrate that feeds the anerobic bacteria which turns it into nitrogen gas that can then escape to the atmosphere. Its a VERY efficent means a export. The only issue is that the critters will tend to end up as a very small group of only one or two types due to their ability to outcompete others. This is a bad thing as biodiversity is the key to effective processing of nutrients so you need to boost the diversity from time to time with either live sand from someone elses tank or one of the "critter packages" on the internet.
As to the phosphate issue, since phosphate cannot be turned into a gasous form it has to be stored in the biomass itself and within the sand grains themselves. Phosphate attaches to the sand grains and is effectively "removed" from the water column. This is the "ticking timebomb" issue. Its a fact that there is a saturation point where no more phosphates can be stored so the water begins to absorb it back via diffusion(ie if the water itself contains more phosphate than the sand, the sand will absorb it. If the sand has more phosphate in it than the water, the water will absorb it.) so you need to siphon off a portion of the sand and replace it with new on a scheduled basis. You can tell when this needs to be done by keeping track of free phosphate via testing but its easier to just replace some bianually or quarterly that way you dont need to be as diligent with testing.
Sand size is VERY important. It needs to be as small as possible to not allow detritus to build up in it and also to allow worms and gasses to pass through the channels the worms create. There is an issue with having rock sitting directly on top of the sand. These areas cannot be turned over by the worms so theres a risk of these areas becoming sulphur zones and compacting and clumping up or even getting hard as a rock not allowing these areas to diffuse. So I tend to agree that DSB's are best used remotely with no rock on top of it...intank can be done but there are more risks with this.
Also, you have to make sure you dont have predators of the plankton in the tank that will reduce their numbers significantly, another good reason to have it remote...
lol, i want my dsb in my main display though. I dont want BB or shallow. I think DSB looks nice.
See above and use the search function for "in-tank DSB" to make sure you understand the risks of this and ways to prevent problems. As others have said a big problem is flow in an sps dominated tank blowing fine grain sand. This WILL cause problems with a DSB. You do not want to stir the sand up, the critters should be the ones doing this to prevent large amounts of nitrogen and sulfer gases from being released all at once. If this is your first reef tank I reccomend a shallow sand bed in the main tank unless you are really familiar with DSB's by reading til your head hurts. Youll have a more forgiving tank that way. Try out the DSB in a section of your sump that can be taken offline if problems arise.
