saraiva said:
DougSupreme
Thank you for the correction, i mean " how many pints to drain each 8 hours"
There are three different approaches to using CPW that I have experimented with.
1) Draining through the CPW for weekly water changes.
2) Periodic short term daily pulse flushing to drain through the CPW
3) Continuous low flow rate wasting back into the system using the CPW.
If you did nothing more than use (1) your DSB would benefit in that it would never build up with sulfide waste and go sour backing into the DSB. I use this in conjunction with (2) and (3).
Short term flushing (2) keeps CPW from short circuiting when wasting small amount daily. It assures of a more uniform removal across the DSB. I recommend you removed a couple of gallons per day using this method, divided into 3 or 4 periods over the 24 hours.
I am presently testing using (3) but it appears that when continously draining nitrates are extracted from the DSB. I have added a denitrification stage to address this.
Is any one method better than the other? I am not sure yet. The main thing is to keep the DSB from going sour, (1) does this. I am not sure if (2) and (3) help the overall treating of waste yet.
Point of interest. Yesterday I cleaned up the interface of the bed with the front of the tank. All that goop showing bothered me. I cleaned it with a high pressure water nozzle fed from the recirculation system. It looks clean and nice again with all white CC. Like a new tank. It made a real mess with detritus floating around for a few hours, but the tank looks clean again and none of the coral or fish were lost or overly bothered by my clean up. I filtered with a side stream through filter floss to remove as much of the floating detritus I could. Some of the SPS seemed to enjoy the new source of food. I didn't check for nitrates, but I figure I dumped some back into the system and it will take a few days to fully recover. I knew my DSB wasn't full of sulphides so I wasn't too concerned about upsetting the tank balance.
Interesting point is that the nitrogen gas bubbles deep in the bed, that I cleaned off in the process, were forming again in the bed with a few hours. Denitrification didn't lose a beat. All of this fear of disturbing the DSB denitrification process and it taking weeks to recover is unfounded. One the bacteria is seeded in the bed, it will recover quickly as the aerobic bacteria uses up the oxygen.