Originally Posted by goodwin9
I have been asked on a number of occasions about the sand filters that I use on my systems and why they were needed.
The following explanation is from Fran Metzger, the owner of The Aquarium Company and builder of my tanks.
"In all of the aquariums that we run with a refugium and liverock on, our Nitrates have been zero. Even on our wet/dry systems with the reticulated foam and liverock in the sump, zero. After 10-12 years, zero. The denitrafication cycle is a transgression from the most deadly components, ammonia to less lethal nitrite to further less lethal nitrate and I have found Nitrate handled with the system itself. None of the filtration is working at even close to its potential. The redundancies are there for you need them to avoid the spikes.
If you think about it, the sand filters and all aerobic filtration can only produce Nitrate because they are converting even more toxic ammonia. If you have Nitrate, it is converted ammonia and while Nitrate may not be great for SPS, ammonia will kill them quicker.
The protein skimmer is such a great filter because it is removing protein even before it can decay into ammonia, completely skipping past the nitrogen cycle. That is why you hear of people running a reef with just a skimmer. Not my idea of the perfect system. If there ever comes an event in the aquarium however that overpowers the skimmer, it's essential to have the back up.
Ammonia itself can be stripped as a gas, also skipping the rest of the nitrogen cycle. That is where the bioball was born as a diffusion device that should be counter flowed with air in a tower to strip ammonia gas. It has been turned into something far less effective however and used as a biological culture bed."
I hope this helps explain the purpose of a sand filter. I just know that my other systems have worked with them, so I wanted them on my new tank.
Hey Goodwin,
Thxs for the explanation but what is the mechanism that does it? Does something "turn over" the sand? Under sand grates that suck through it? How does it filter?
ALso, I think you need to get everyone following your thread to pitch in and buy one or two huge SPS pieces for you! If we all gave $5 you could get some whopper pieces!
Mc
