Refugiums, detritus, live rock in sump in an SPS tank

[rocknut]

I am hoping to get some opinions and guidance from some of the fine folks here on the SPS forum regarding refugiums, detritus, live rock in sump, etc. I know that this isn't an SPS specific question, but I am hoping for some opinions/ideas in direct relation to how these things effect an SPS system.

First, a quick bit of background on my tank: my 150 gallon has been up and running for 18 months at this point. First seven months were great, I was running biopellets and was getting great growth/color, and then I had a huge issue with dinoflagellates that lasted from last April thru September, and I ended up losing about 95% of the coral in my tank. Ultimately, I believe the cause was primarily my improperly maintained DSB, that I gradually removed over the summer. Removing about 80% of the sandbed and taking it down to about an inch, seemed to do the trick, but the dinos would still keep coming back (much less each time, but still an issue). It wasn't until the end of September that decided to do the following: increased alk from 7.5 up to 10-11dkh, and I started dosing Red Sea No3Po4-X. Long story short: within two weeks, the No3Po4-X had the dinos under control, and things have been on the road to recovery the past 4-5 weeks. I have since brought the tank back down to 7.5 dkh, lights are running full steam ahead, and colors are starting to return (no growth yet), but things seem to be looking up.

However, even after 8 weeks of No3Po4-X dosing, my No3 levels have stayed between 10-20, using the Red Sea test kit. My Po4 levels are almost undectable (2 ppb using the Hanna ULR, which translates to 0.002 or something close to that). As part of my approach to fighting the dinos, I pulled the biopellets offline back in July, and added a 20 gallon frag tank to my setup, and filled it with live rock in an effort to boost up the natural filtration in the tank hoping to avoid any sort of carbon dosing. The frag tank is part of my chiller loop, and empties into a refugium compartment in my sump where I have additional live rock, and a ball of chaeto.
With the added live rock, the ball of chaeto, and dosing the No3Po4-X, I am surprised that my No3 levels haven't fallen more? I have a fairly large skimmer that I clean regularly, and skims great; I do 10 gallon water changes using ESV salt twice each week (every Saturday, and every Wednesday) vacuuming the shallow sand bed with each water change; and I vacuum any detritus I see in the sump or frag tank several times each week. I do have a moderate fish load (4 anthias, 4 chromis, 1 Melanurus Wrasse, 1 Leuitenant Tang, and a Diamond Goby) but only feed 1 cube of rinsed mysis at night, and some flake in the morning. However, that seems to be the key: there is a LOT of detritus in the refugium compartment of my sump, and on the bare bottom of the frag tank. Unfortunately, when I set this tank up, I didn't leave room for filter socks, thinking that I would use a big skimmer and pull out any detritus that way. So what I am hoping to get some feedback on is this: am I doing more harm than good with all the live rock in the frag tank and refugium? Yes I have added additional filtration, but is this adding so much detritus to the system that it is driving up my No3? With the dinos hopefully behind me, I am trying to take some steps to get this tank dialed back in again, so I can take a more hands off approach, not tinker with stuff, and just keep up on maintenance and let the tank do its thing, but this is a sort of nagging issue. I could put the live rock in plastic "œbaskets" and lift them up every week to vacuum underneath, but that still doesn't feel like a long term solution?

I would love to get some feedback on this so I can put together a plan going forward.

Thanks in advance for taking the time to read this, and for sharing your thoughts!

 

[socent33]

One more piece of info to help with the context for diagnosis: how do you maintain Alk and Ca- Two part, reactor or kalkwasser?

 

[rocknut]

One more piece of info to help with the context for diagnosis: how do you maintain Alk and Ca- Two part, reactor or kalkwasser?

I am using ESV B-Ionic 2 part for Alk and CA, dosed with a Profilux doser. Thanks for your response!

 

[jdamon]

I tried running without filter socks for the first few months of my 150, but had to start using them. There is just too much crap floating around. My sump is just a 40 gallon tank with acrylic dividers, and I made a small compartment in one corner where the two return hoses enter the sump. The hose is flexible enough to be pulled out of this small corner section, and I have been placing a sock over the end of the hose and the sticking the hose back in the corner box. This holds the sock fine. You could also just place the sock over the end of the return hose and suspend the sock with a piece of string or something from the side of the sump. I also recently tried 300 micron socks as the 100 and 200 versions were clogging up so fast, less than a day, and I am very happy with them. I think you could Benifit from some mechanical filtration. Good luck!

 

[offdahooklikeoj]

I think for a full blown sps system that you would eventually go back to some form of carbon dosing. Trying to add filter socks will definitely help capture some of the detritus from settling in the sump. I have never been a fan of refugiums or extra live rock in the sump for bio filtration, I think they create zones for nutrients to build up and is counter productive, So I would remove them. I believe you have enough live rock in your display.

I recently stopped using filter socks for a few weeks to see what effect it had on my tank. Quite honestly I've noticed that without them food keeps circulating throughout the tank for my corals and filter feeders to grab a hold of. Also all of my detritus settles into my skimmer section of the sump, fine for me since either the skimmer will get it or I will once I perform a water change. I might actually stop using filter socks for the time being, or at least until i need them. Unless your changing your filter socks every 3-4 days, they eventually become nutrient rich zones, which may not be what your looking for.

I dose my 2 part via bubble magus dosing pumps, set it and forget it for the most part (until corals grow).

 

[newbie2]

I am by no means an expert, but had a similar situation this fall. I have a 120gallon tank and for a while I had nitrates around 35 and couldnt get them down. I was at 64ml vinegar and up to 15ml NO3PO4x and couldnt get it down. I ran like this for about 3 months with my nitrates only falling to 25. My PO4 was between 0 and 5 ppb with hanna. I was in the same boat and added some liverock to the sump to hopefully help, and started to vacuum sump weekly with water changes but nothing worked.

What finally turned the corner for me was taking out my GFO and getting my phosphate number up. Once I had around 25-50 ppb PO4 my nitrates came down in about 3 weeks. I now sit around 1ppm and have put the GFO back online (PO4 back down to under 10ppb on average). My vinegar dosing is down to 40ml a day and I only add about 5ml NO3PO4x every other day now.

I will admit that I had more algae growth on the glass while I took out the GFO however, so there is a risk that you may get some growth until you get the Nitrates and phosphates down again. I still have the liverock in the sump, and have continued to vacuum my sump, but perhaps not as diligently.

Definetly not saying it will work in every case but it seemed to work in mine.

 

[DiscusHeckel]

Hi,

Do you use RODI for water changes? If so, do you test the TDS of the effluent?

How much flow do you have in your tank? Do you think you avoid dead spots around your rock work?

What is the growth rate of your chaeto? Does it look healthy? Do you supplement it with iron and possibly iodine?

In my tank, nitrates has always been 0.2 ppm or less ppm (Salifert). I cannot raise it even if I dose amino acids. My sump gathers awful lot of detritus, especially in the section where cheato is kept. I also have live rocks in my sump. They also collect detritus. I do not think detritus in your sump is the cause of nitrates.

In my opinion, you need to focus on your water source, flow in your display tank as well as your nutrient export strategy.

 

[rocknut]

I am by no means an expert, but had a similar situation this fall. I have a 120gallon tank and for a while I had nitrates around 35 and couldnt get them down. I was at 64ml vinegar and up to 15ml NO3PO4x and couldnt get it down. I ran like this for about 3 months with my nitrates only falling to 25. My PO4 was between 0 and 5 ppb with hanna. I was in the same boat and added some liverock to the sump to hopefully help, and started to vacuum sump weekly with water changes but nothing worked.

What finally turned the corner for me was taking out my GFO and getting my phosphate number up. Once I had around 25-50 ppb PO4 my nitrates came down in about 3 weeks. I now sit around 1ppm and have put the GFO back online (PO4 back down to under 10ppb on average). My vinegar dosing is down to 40ml a day and I only add about 5ml NO3PO4x every other day now.

I will admit that I had more algae growth on the glass while I took out the GFO however, so there is a risk that you may get some growth until you get the Nitrates and phosphates down again. I still have the liverock in the sump, and have continued to vacuum my sump, but perhaps not as diligently.

Definetly not saying it will work in every case but it seemed to work in mine.

Hi Newbie2,

Thanks for sharing your thoughts. Sounds like you were in the same boat as me regarding an imbalance in your N ratios. I understand that having Po4 as low as I do (and as low as you did), limits what the carbon source can do to reduce the No3. The problem for me is that I haven't run any GFO since July, so I don't have anything to pull offline to try to increase my Po4. I know that some people have actually dosed some Po4 to help bring down N03, but I am really hesitant to do this because the last thing I would want is to kick up another bloom of dinos by bumping my nutrients up too high.

 

[rocknut]

Hi,

Do you use RODI for water changes? If so, do you test the TDS of the effluent?


Hi DiscusHeckel, thanks for sharing your thoughts.

I use a four stage RO/DI Maxcap system to make up my water. In fact, since I work about five miles from Spectrapure, I took in my entire RO/DI unit to their factory back in June when I was battling the dinos so they could go thru it and make sure everything was tip top. However, this brings up one point that has me a bit confused/baffled: I always get 0 TDS water (they calibrated my dual inline meter at the factory), and was told that as long as I was getting 0 TDS water, my water had to be clean. Based on my understanding of the MaxCap system, as long as you change the first DI stage when it hits a TDS percentage of the RO effluent, you can prolong the life of the final DI stage considerably. So, my water coming out of the RO membrane and going into the final two DI stages sits right at 5 or 6, so I have always changed the first DI stage when it begins to show a TDS of 1. My final DI stage was installed back in February 2014 because I only recently started to show a TDS of 1 coming out of the first DI stage (so still 0 TDS from the final stage). Just for kicks, I went ahead and tested the No3 of my mixed salt water made using this RO/DI, and the reading was off the chart - even though the TDS was zero with my handheld meter.

So, I changed out all four filters (sediment, carbon block, and both DI stages), and made new water, and now I am showing zero No3. Of course, to make things less cut and dry, I had just received a refill on my Red Sea No3 Pro Test kit, and used this when I did this testing. The refill kit showed the No3 off the chart, but my original Red Sea Pro Test (that is not expired), showed a very low level of No3. With this in mind, I'm not 100% sure what the No3 of the newly mixed water really was, because obviously, one of those test kits is not accurate. Since changing the filters on the RO/DI, BOTH kits now show zero No3.

 

[rocknut]

Hi,

Do you use RODI for water changes? If so, do you test the TDS of the effluent?

How much flow do you have in your tank? Do you think you avoid dead spots around your rock work?

What is the growth rate of your chaeto? Does it look healthy? Do you supplement it with iron and possibly iodine?

In my tank, nitrates has always been 0.2 ppm or less ppm (Salifert). I cannot raise it even if I dose amino acids. My sump gathers awful lot of detritus, especially in the section where cheato is kept. I also have live rocks in my sump. They also collect detritus. I do not think detritus in your sump is the cause of nitrates.

In my opinion, you need to focus on your water source, flow in your display tank as well as your nutrient export strategy.

Also, the tank is 5 feet long, 2 feet tall, and 2 feet wide (150 gallons), and I am using two Tunzes (6101 & 6105) along with a wavebox for flow. Seems to be pushing enough flow with these pumps? Especially since I don't exactly have any corals blocking the flow (sigh). :lol:

When I first added the Chaeto, it had amazing growth (this was over the summer before I started using No3-Po4-X). Since adding the carbon dosing, the growth has slowed quite a bit, which is to be expected I guess. Honestly, I assumed that I would hit a point where it would die off and I would remove it. I have started adding a drop of Lugol's Solution to the tank probably four times per week, so maybe this will help?

You also bring up a great point regarding strategies for nutrient export. This was a major "light bulb" moment for me about a year ago: the high nutrient import, and high nutrient export school of thought. One comment that I read awhile back has really stuck with me: you have to be able to import lots of nutrients, but you must have a system in place to process and remove these as well - its when there is a bottleneck in the process that you run into problems. When the start to finish process breaks down, and nutrients are left unprocessed in the tank to rot and turn into Po4/No3. Definitely feels like I have a "bottleneck" in the process.

 

[rocknut]

I think for a full blown sps system that you would eventually go back to some form of carbon dosing. Trying to add filter socks will definitely help capture some of the detritus from settling in the sump. I have never been a fan of refugiums or extra live rock in the sump for bio filtration, I think they create zones for nutrients to build up and is counter productive, So I would remove them. I believe you have enough live rock in your display.

I recently stopped using filter socks for a few weeks to see what effect it had on my tank. Quite honestly I've noticed that without them food keeps circulating throughout the tank for my corals and filter feeders to grab a hold of. Also all of my detritus settles into my skimmer section of the sump, fine for me since either the skimmer will get it or I will once I perform a water change. I might actually stop using filter socks for the time being, or at least until i need them. Unless your changing your filter socks every 3-4 days, they eventually become nutrient rich zones, which may not be what your looking for.

I dose my 2 part via bubble magus dosing pumps, set it and forget it for the most part (until corals grow).

Honestly, I designed my sump to not use any filter socks for the reasons that you mentioned. The tank is five feet long, and has a coast to coast, five foot long overflow running the entire back length of the tank. My plan was to use my Tunze Wavebox to keep junk in the display tank in suspension, and then use the maximum amount of surface skimming to move detritus into the sump, where my big skimmer would then pull it out. My thought was that the detritus would stay in suspension so either: A) the corals and filter feeders would get it, or B) the skimmer would get it. Still seems like a good theory to me?

I'm still hoping that I can get my No3/Po4 levels under control using A) good skimmer, B) lots of flow, C) carbon dosing, and D) regular water changes, so that I can eventually not need the refugium and macro algae.

I also appreciate your feed back regarding the amount of rock in my display being sufficient for filtering my system.

 

[rocknut]

I tried running without filter socks for the first few months of my 150, but had to start using them. There is just too much crap floating around. My sump is just a 40 gallon tank with acrylic dividers, and I made a small compartment in one corner where the two return hoses enter the sump. The hose is flexible enough to be pulled out of this small corner section, and I have been placing a sock over the end of the hose and the sticking the hose back in the corner box. This holds the sock fine. You could also just place the sock over the end of the return hose and suspend the sock with a piece of string or something from the side of the sump. I also recently tried 300 micron socks as the 100 and 200 versions were clogging up so fast, less than a day, and I am very happy with them. I think you could Benifit from some mechanical filtration. Good luck!

Honestly, I am really kicking myself for not designing a more flexible sump design, at this point. I have two 1 1/2" hard pipes that run directly into my first sump compartment. The compartment itself is only like 2 1/2" wide (long and narrow before going into the skimmer compartment), so it is ridiculous trying to squeeze in a filter sock under the pipe. I'm wondering if I couldn't design some sort of tray that would sit above this section with filter sock holders, but it might require me to get a new sump. That would probably be my last choice solution if only because of the $$$ involved. However, if it comes to the point that that is the only way I can get this under control, I might have to consider it. I might need to post a picture to show how I have painted myself into a corner, design wise, with adding a filter sock.

 

[rocknut]

One more thing: tested the No3 in my display tank last night. Using the original Red Sea Nitrate Pro Test kit (the one that has all liquid reagents, and the color wheel that goes from blue to pink) my No3 is right between 4 and 8. When I use the refill pack (one liquid reagent, and two powder reagents, and the color wheel that goes from pink to dark pink) I get 32...So, not quite sure which level is accurate at this point. I would think that the 32 level would produce some hair algae in the display? Either way, still want to have a plan with how I am going to run my sump (rock or no rock, etc), but will probably need to buy ANOTHER No3 test kit and see if I can figure what my level really is...

 

[jda]

Here are some key facts to know about detritus that I have gleaned over the years that works for me:

• It needs to be removed at some point.
• Most phosphate leaves the fish/inverts through urine.
• Phosphate leaves most detritus pretty quickly - before it settles/sinks in most cases. When people call sand a phosphate sink, it is more a reference to it not functioning to process the phosphate anymore, not actually being full of phosphate.
• The main issue that I have with lots of detritus is that it gums up the works - live sand and live rock surfaces... sand needs to be cleaned and live rock needs to be blown off.

Here is an excerpt from RHF about phosphate and urine and feces from anther thread:
I am, as it happens, an expert on phosphate metabolism. I've studied it for more than 20 years, and have invented products that sell more than a billion dollars worth each year correcting hyperphosphatemia in people.

There is a flow chart in this link which shows the relative excretion of phosphate in urine (which is almost totally inorganic phosphate) and in feces (which is a combination of organic and inorganic phosphate).

https://www.inkling.com/read/medica...-2nd/chapter-52/calcium-and-phosphate-balance

The inorganic phosphate in urine excretion dominates, even if you ignore all of the inorganic phosphate in the feces. Then you seem to assume that all of that feces ends up in the substrate, which is utterly untrue. Other macroscopic creatures eat it, sometimes over and over. I had a kole tang that loved to eat my yellow tangs feces as fast as it came out. That drops the original phosphate ending up in feces by another factor of, say, based on the data above, three. Each cycle drops it significantly.

At the end of the day, yes, there obviously is phosphate making it to the substrate (as I've agreed along), but it is not the dominant player in phosphate balance in a reef tank.

I would argue that most of your issues is the use of biopellets early. You basically inhibited the tank from finishing the end of the cycle where anoxic zones would develop and you could process N naturally. I would suggest that you stop adding the organic carbon and let the tank build up the anoxic bacteria.

Clean the detrius out on a regular schedule, but getting it right away is probably not going to help much since most of the phosphate is long gone. I would siphon the sump and use a gravel vac on the sand (small portions slowly over time).

I keep live rock in my sump for storage. I just swish it off and use the sump water for a water change about every 6 months. I have undetectable levels of N and P and use no organic carbon or GFO.

 

[rocknut]

Here are some key facts to know about detritus that I have gleaned over the years that works for me:

• It needs to be removed at some point.
• Most phosphate leaves the fish/inverts through urine.
• Phosphate leaves most detritus pretty quickly - before it settles/sinks in most cases. When people call sand a phosphate sink, it is more a reference to it not functioning to process the phosphate anymore, not actually being full of phosphate.
• The main issue that I have with lots of detritus is that it gums up the works - live sand and live rock surfaces... sand needs to be cleaned and live rock needs to be blown off.

Here is an excerpt from RHF about phosphate and urine and feces from anther thread:
I am, as it happens, an expert on phosphate metabolism. I've studied it for more than 20 years, and have invented products that sell more than a billion dollars worth each year correcting hyperphosphatemia in people.

There is a flow chart in this link which shows the relative excretion of phosphate in urine (which is almost totally inorganic phosphate) and in feces (which is a combination of organic and inorganic phosphate).

https://www.inkling.com/read/medica...-2nd/chapter-52/calcium-and-phosphate-balance

The inorganic phosphate in urine excretion dominates, even if you ignore all of the inorganic phosphate in the feces. Then you seem to assume that all of that feces ends up in the substrate, which is utterly untrue. Other macroscopic creatures eat it, sometimes over and over. I had a kole tang that loved to eat my yellow tangs feces as fast as it came out. That drops the original phosphate ending up in feces by another factor of, say, based on the data above, three. Each cycle drops it significantly.

At the end of the day, yes, there obviously is phosphate making it to the substrate (as I've agreed along), but it is not the dominant player in phosphate balance in a reef tank.

I would argue that most of your issues is the use of biopellets early. You basically inhibited the tank from finishing the end of the cycle where anoxic zones would develop and you could process N naturally. I would suggest that you stop adding the organic carbon and let the tank build up the anoxic bacteria.

Clean the detrius out on a regular schedule, but getting it right away is probably not going to help much since most of the phosphate is long gone. I would siphon the sump and use a gravel vac on the sand (small portions slowly over time).

I keep live rock in my sump for storage. I just swish it off and use the sump water for a water change about every 6 months. I have undetectable levels of N and P and use no organic carbon or GFO.

Thank you so much for posting that useful information! Although I couldn't have told you specifically why, I suspected that my biopellets were to blame when the dinos first started to bloom last spring. Like I said, I was initially able to get rid of them over the summer by doing water changes every 3-4 days, and by siphoning/removing most of the sand bed during these water changes. Once I had the sand bed reduced to about 1 inch on average, the dinos were drastically reduced. I think it was an imbalance in the N ratio in the tank that originally sparked their bloom, along with a bunch of stored nutrients in my improperly managed DSB.

Once I got rid of the dinos in June/July, I decided to completely pull the biopellets, and increase the amount of live rock for additional filtration, and add a refugium with macro, etc. My thought at this point was to "go back to basics" and run the tank in a more traditional, less complicated way (refugium, macro, added live rock, GFO & GAC). This did seem to work, but by the end of August, early September (going from memory, don't have my notes here with me), the water quality started to suffer, and the dinos started to reappear. At this point the Po4 was still low, to basically undetectable, but I was getting an No3 reading of 3-4. The live rock in the display looked very "dirty" and could blow off a huge cloud of junk on a daily basis. I reasoned that the reappearance of the dinos, and the first ever appearance of GHA was pulling the nutrients from the water before I could measure it with my test kits. I basted all of the live rock on a daily basis, scrubbed with a tooth brush, and kept doing twice weekly water changes at this point, but by the beginning of October, the dinos were back full swing.

It was at this point that I decided to bump up the alk (to help maintain a consistent higher ph for one thing), and start dosing the Red Sea No3-Po4-X because it seemed that the tank was failing, and the dinos would soon start growing over my corals and killing them, again, so I had nothing to loose. To my surprise, really, the No3-Po4-X did work, and the dinos were completely gone in two weeks, and GHA was receding. Within a month (by the beginning of November), all the GHA was gone as well.

I bring this up because at this point I am hesitant to stop dosing the No3-Po4-X because I don't want to give the dinos a foothold to come back again? Dealing with dinos was by the far the most frustrating reef related thing I have ever dealt with. However, if some imbalance in my tank, and its inability to properly process Nitrates is/was the cause of the dinos in the first place, that definitely puts a different spin on things...

 

[rocknut]

Thought I would post a few photos of my sump configuration:



This shows how the frag tank sits next to the display tank. I have a chiller loop that feeds first the chiller, then the frag tank, which then drains into the refugium compartment of my sump (the one with the pink/red light over it). The frag tank was originally intended to be a full on external refugium, but since I started carbon dosing, it is just a place for extra live rock at this point, with a few frags.






Here is another that shows the location of the refugium compartment in the sump.







This illustrates a little better why I would have such a hard time adding any filter socks. The two pipes at the back, behind the skimmer compartment, are the actual drain lines from the display. They drain into a compartment that is 18" long, but only about 2 1/2" wide, so it is basically impossible to get the socks in place.

 

[jda]

The tank should be able to handle N on it's own with the rock/sand, but you will need to quit adding organic carbon for a while so that the anoxic zones will establish. Is No3-Po4-X a organic carbon source - if so, it is doing the same thing (nearly) as the biopellets. It can take a year for a tank to finish the cycle to where Nitrate gets converted into N gas by anaerobic bacteria in equilibrium - 6-9 month old tanks with nitrates is OK, and even desirable, so that the anoxic zones develop. Even though your tank is older, I fear that you have delayed this part with the organic carbon.

Most tanks with aragonite can handle P pretty well too, again, over time.

I use sand. 2-3 inches and I vacuum about 10% every quarter so that I get to all of it every 3 years, or so. Sand that is not bogged down is sludge is quite beneficial IMO.

 

[rocknut]

Hi,

Do you use RODI for water changes? If so, do you test the TDS of the effluent?

How much flow do you have in your tank? Do you think you avoid dead spots around your rock work?

What is the growth rate of your chaeto? Does it look healthy? Do you supplement it with iron and possibly iodine?

In my tank, nitrates has always been 0.2 ppm or less ppm (Salifert). I cannot raise it even if I dose amino acids. My sump gathers awful lot of detritus, especially in the section where cheato is kept. I also have live rocks in my sump. They also collect detritus. I do not think detritus in your sump is the cause of nitrates.

In my opinion, you need to focus on your water source, flow in your display tank as well as your nutrient export strategy.

Also, just read thru your tank thread: amazing tank you have! I hope that thru some hard work and some careful planning, I can get my tank 1/2 as nice as yours some day.