Dr-BYTES said:
Idrhawke
My cpw system has been set up for 2 months now. I have noticed that overpowering rotten egg smell everytime i drain a small amount of the cpw waste to throw down the drain. I did a good flush and i will now commence a moderate drip rate into my sump and monitor the
nitrates and phosphates. will post results in a months time
Good show Dr-BYTES.
my nitrates as of to day are 5ppm and no readable phosphates......I do not have a processing system its just going into the sump where the skimmer is. I want to see if a constant positive flow through the bed will reduce nitrates and the 5ppm is from the WC
This is still a new setup as far as livestock is concerened . the tank and live rock have been setup since Jan went through various alge blooms etc but i did not add any live stock till end march.
Your are finding about what I found. The nitrates in the bed discharge are probably because of several reasons. Short circuiting at the extreme low flow rates, the bed hasn't reached a balance and reached full biological stability, or simple not enough de-nitrification time. Time may help to bring it into balance. I elected to add a de-nitrification stage because it was easy enough to do and doesn't hurt anything.
As I have noted, the bloom of nitrogen bubbles in my substrate leaves little doubt that nitrification is taking place. I suspect the flow through the bed may all be moving through a single area and allowing the nitrates in the water column to simply pass through and is short circuiting.
i have today discussed the dsb question with a water treatment
specialist he is by no means a reefer here is his thoughts . He agrees the plenum under the sand bed is a asset but my procedure is flawed what we should not have is bacteria deep in the bed he say's that the best way to approach a dsb plenum
would be to drain waste from the bed but to back flush the bed with fresh salt water although the frequency of how often to drain and backflush is unknown i guess i may experiment . Any thoughts on this
Your friend may know how to treat water but he doesn't know how to treat water with waste in it.
Just think about what you are doing wrong with reverse flow in the substrate. You are feeding the anoxic zone on the bottom with oxygen and you are pushing the untreated waste on the upper surface of the bed back into the water column before it is processed......all wrong. You will load you system up with nitrates and nitrites. Don't run CPW in reverse. Also running in reverse can plug up the plenum holes from the inside.
Keep a record of your nitrate concentration in the discharge and the water column. I have not found any signification change in my system and I will continue to feed through my de-nitrification process to address it. I have a heavy fish load. You may find different results.
Everytime I feed heavily I can see the small patches of hair algae lightly bloom. It is on the rocks that breaks the surface. It is telling me nitrates and phosphates have increased. Within 24 hours the hair algae dies back as they rapidly decrease.
Keeping a system in balance is not simply addressing one area of a good reef system design. It is doing a number of things right since they all work together in making a reef system work.
As example, all the guys that have gone BB or plastic bottom have found out how critical it is to improve the tank flow rates and the need for more efficient skimmers. They all use much larger pumping systems and have even added things like eductors to signifcantly increase tank turn over. This helps to keep the waste from collecting in corners on the bottom and keeps it available to be treated with a good skimmer. I agree totally with this approach. In fact, if they did this while they were using a DSB or a substrate bottom*, they would have greatly reduced the biological loading on that part of the tank biological processing and may never have had convert to BB to attempt to solve their waste issues.
My point is we need to design the whole reef system better from the start. A weakness in one area will put additional biological loading on the rest of the tanks biological processing areas. CPW needs to be combinded with high flow rates, a good skimmer, etc.
*Note....with high flow rates in a tank, sugar sand needs to be replace with CC to keep it from blowing all over tha tank.
I have used high flow rates, in my 45g tank, from a Dolphin 3000 pumping and mixing in my system and have had good skimming from the start. Just because you have CPW doesn't mean these elements are not required for long term success.
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