Re: DSB and new tank setup - Follow-up... Surge systems/design... fixing...  2/18/08 Hello Bob:) Just a follow-up since the last time. I started the surge (CSD) yesterday and it fires sweetly. It fills around 20 odd liters and my main tank water lines changes by 3 inches between surges. <Nice> Problem is, sometimes it takes a while to break siphon. I have tried all the tricks and still not able to get 100% predictability in the start stop sequence. <Yikes... need a fail safe mechanism here... like a drain line/port above the transit volume sump... to drain lest it overfill> I tried by cutting the surge tank pipe in a 45 degree angle, drilled an air vent just above the waterline in the discharge pipe. Can not seem to get it to consistently stop. It takes a while (sometimes) for the siphon to break but does break in the end. This delay to break siphon causes excess bubbles (AKA salt crepe) while the air is being pulled in. sometimes it lasts for 2-5 min. Any ideas how I can overcome this? <Perhaps adding an aspiration line... a rigid piece of tubing would be better than flexible... of 3/16" diameter should do... arranged down into and near the bottom of the overflow/siphon, and terminating higher than this... to allow air intake> My surge lasts for 1 min and takes 3 min to start again. <Mmm, a minute for discharge? This is a bit long... is there a simple way to expand/enlarge the siphon/discharge line and through-put?> This gives time for the water level in the display tank to reduce so it can accommodate the next surge. Also the air bubbles go away. I can only increase the frequency by reducing the surge volume proportionately. <Mmmm, I wouldn't take this route> Because there is currently just about time (a 10 to 20 seconds buffer is there still) for the water to flow down to the sump before the next surge starts. <Not enough time to suit me...> Do I need an additional powerhead to keep some flow in the 3 min? <Mmm, likely this would be of benefit> As of now the ONLY circulation is the surge that is filled from the sump return pump. <Mmmm, not enough... look into other means... posted on WWM> Currently my Nitrates are at 2.5 to 5 ppm range. My DSB is not reducing nitrates below this. <This is fine...> My feeding is really sparse and I feed only 1 small cup coral and 1 moon coral with shredded squid pieces that are target fed by placing the pieces on the polyps. No fish or other inverts in the 120 gallon tank. Source water does not have nitrates. Where is the nitrate coming from? <Food, life processes> Am actually HAPPY that a small amount of nitrates is there as I know corals use this. But just curious, will this not become completely zero? <Not likely> The amount has not changed since last 2 weeks. <I would not be concerned> Can a 6" diameter moon coral finish off a few 100 pods in a week? <Not if they're smart...> I think I see a substantial reduction in my pod population and have not put any predator in except Palythoa and one moon coral. <There are many other life forms present... there is more to see the more you look... try a flashlight at different times at night...> I have an idea for a nice in-tank refugium. Can I cordon off the back of my tank around 2" to 3" with a fine PVC  mesh. Inside I could have macro algae? <Could> This would give a refugium for the pods as such and at the same time give a supply of macro algae for the herbivores to nip at without being able to finish it off. Do you see any problems that could come up here? <Heeeee! I am able to see a great deal of such potential possibilities...> I see hell lot of brown algae on my back glass. This is where the MH is focused at. <This too shall pass, change...> So much that it has started to spread on the substrate behind. The only herbivores are a dozen snails. Is this enough? <You'll see> I don't want to put in fish yet as the pod and other items are yet to form a sustainable population. Is this because I am yet to setup my skimmer? <Would help...> Will my pods eat this brown algae? If not then I can always clean it. Cheers and Thanks YET again :) Ranjith <Many types of "brown algae" are unpalatable... but there are ways to control, limit all life. Bob Fenner>

Re: DSB and new tank setup, actually surge system pb - Follow-up... <<ScottV input>>  -02/20/08 Hi Bob, I thought USA folks were having a holiday yesterday. <Only the civil servants/masters... Our country is becoming an aristocracy> But, it was great to get your response as always :) Have commented below your comments in the below mail. Please let me know what you think. Cheers Ranjith Subject: Re: DSB and new tank setup - Follow-up Hello Bob:) Just a follow-up since the last time. I started the surge (CSD) yesterday and it fires sweetly. It fills around 20 odd liters and my main tank water lines changes by 3 inches between surges. <Nice> Problem is, sometimes it takes a while to break siphon. I have tried all the tricks and still not able to get 100% predictability in the start stop sequence. <Yikes... need a fail safe mechanism here... like a drain line/port above the transit volume sump... to drain lest it overfill> <<Scott V. here, I will second this to emphasize its importance.>> >>Ranjith - Agreed. Wanted to check that the surge is fine before taking the additional effort to get the fail safe measures in. Will do it this weekend. Meanwhile the wife is kind enough to watch over. I tried by cutting the surge tank pipe in a 45 degree angle, drilled an air vent just above the waterline in the discharge pipe. Can not seem to get it to consistently stop. >This won't do it... the aspirator needs to go down inside the drain line...< It takes a while (sometimes) for the siphon to break but does break in the end. This delay to break siphon causes excess bubbles (AKA salt crepe) while the air is being pulled in. sometimes it lasts for 2-5 min. Any ideas how I can overcome this? <Perhaps adding an aspiration line... a rigid piece of tubing would be better than flexible... of 3/16" diameter should do... arranged down into and near the bottom of the overflow/siphon, and terminating higher than this... to allow air intake> >>Ranjith - I did add an aspiration hole (read as just drilled a hole) just above the max water level after the surge fires in the "Discharge" pipe. Will this not be the same as an aspiration in the siphon pipe? >No, it is not... I do wish I had a diagram to refer you to... Am going to send this to our most adept "aquarium engineering" person, Scott Vallembois, for his better input< << An aspiration hole will not cut it, you will need an air line at least 3/16' in diameter that goes down into the pipe you are in which you are trying to break the siphon. There will be a sort of 'sweet spot' to introducing air into this to break the siphon quickly, so you will need to slide this line up and down in the line to find this spot. This will take a little experimentation on your part. If it still does not break the siphon fast enough you may need a larger aspiration line. Needless to say, you want to drill your hole to fit the line snugly to prevent leakage and hold the line in place.>> My surge lasts for 1 min and takes 3 min to start again. <Mmm, a minute for discharge? This is a bit long... is there a simple way to expand/enlarge the siphon/discharge line and through-put?> >> Ranjith - Is dangerous I think. Limitations based on the existing 1.25" overflow drilled in the display tank side glass. Even now, the water level rises above the overflow and a MOMENTARY siphon starts into the sump. This helps keep the in and out flow balanced. >A dangerous, untenable prospect... but one that can be solved likely with the aspiration line, rather than decreasing flow rates< <<Consider drilling a second overflow drain for redundancy/peace of mind. I very highly recommend you do this 'there is a lot of water transiting this system at one time.>> Didn't know the need when I made the tank almost 2 years ago. This gives time for the water level in the display tank to reduce so it can accommodate the next surge. Also the air bubbles go away. I can only increase the frequency by reducing the surge volume proportionately. <Mmmm, I wouldn't take this route> >> Ranjith - What is the reason for this opinion? If the surge volume is reduced, then the frequency would increase proportionately. So instead of 20Liters in 60 seconds, I would get 10 liters every 30 seconds (maybe marginally fewer liters). I do agree that the velocity of the surge would reduce MORE than proportionately since the potential energy is reduced due to a smaller water column being siphoned over the same siphon pipe. Because there is currently just about time (a 10 to 20 seconds buffer is there still) for the water to flow down to the sump before the next surge starts. >Just too noisy and unpredictable... In time, "something" slows the flow down the pipe... and an overflow occurs< <Not enough time to suit me...> >>Ranjith - I meant to say that the water level completely drains after the surge and still gives me 10 to 20 seconds after that before the next discharge. Are you thinking in the direction of a blockage in the overflow pipe? If so, then I agree, but, the risk remains even when the surge does not exist and the sump returns into the display directly right? >Not following you here< <<All the more reason for redundant overflows.>> Would it be best if I powered the surge from the tank and throttled the sump return (into the surge) to about half the existing throughput? >Not satisfying either... You want the flow, periodicity (more frequent), just not the sucking/siphoning and danger of overflow< That way, the sump return would be returned to the main display once in every few surges and the water level in the display would be the main volume that circulates between the display and the surge bucket. Do I need an additional powerhead to keep some flow in the 3 min? <Mmm, likely this would be of benefit> >> Ranjith- Ok I will put a 2K liter PH blowing in the direction against the surge to get some chaotic flow. As of now the ONLY circulation is the surge that is filled from the sump return pump. <Mmmm, not enough... look into other means... posted on WWM> >>Ranjith - maybe the PH now and a closed loop later? >Sounds good< Currently my Nitrates are at 2.5 to 5 ppm range. My DSB is not reducing nitrates below this. <This is fine...> My feeding is really sparse and I feed only 1 small cup coral and 1 moon coral with shredded squid pieces that are target fed by placing the pieces on the polyps. No fish or other inverts in the 120 gallon tank. Source water does not have nitrates. Where is the nitrate coming from? <Food, life processes> Am actually HAPPY that a small amount of nitrates is there as I know corals use this. But just curious, will this not become completely zero? <Not likely> The amount has not changed since last 2 weeks. <I would not be concerned> Can a 6" diameter moon coral finish off a few 100 pods in a week? <Not if they're smart...> >>Ranjith - I take that as a "No" :) ? >Correct< I think I see a substantial reduction in my pod population and have not put any predator in except Palythoa and one moon coral. <There are many other life forms present... there is more to see the more you look... try a flashlight at different times at night...> >>Ranjith - Found an "Elysia ornate" in the tank yesterday. Understand these live on specific algae (which is plentiful in my tank as of now). Will it be possible for it to survive and multiply? Also, my Fromias ignore the small squid piece I target feed them. What DO I feed them? >Please see WWM re... and break up your correspondence... too many topics, too long< I have an idea for a nice in-tank refugium. Can I cordon off the back of my tank around 2" to 3" with a fine PVC mesh. Inside I could have macro algae? <Could> This would give a refugium for the pods as such and at the same time give a supply of macro algae for the herbivores to nip at without being able to finish it off. Do you see any problems that could come up here? <Heeeee! I am able to see a great deal of such potential possibilities...> >>Ranjith - could you mention a couple of the worst possibilities? >Not here, now... this email is too long...< I see hell lot of brown algae on my back glass. This is where the MH is focused at. <This too shall pass, change...> >>Ranjith - Ahhh, the spiritual side hee :)) Actually I think it has started to change already. The brown is reducing a bit, but don't see any green taking its place "yet". So much that it has started to spread on the substrate behind. The only herbivores are a dozen snails. Is this enough? <You'll see> I don't want to put in fish yet as the pod and other items are yet to form a sustainable population. Is this because I am yet to setup my skimmer? <Would help...> >>Ranjith - this weekend the skimmer shall be working. >Good< Will my pods eat this brown algae? If not then I can always clean it. Cheers and Thanks YET again :) Ranjith <Many types of "brown algae" are unpalatable... but there are ways to control, limit all life. Bob Fenner> << Good luck, Scott V.>