making a DSB efficient

[treesprite]

I have had a 5" RDSB for I'm guessing about 6 monthss - lost track of time - and am seeing no effect. I am hoping someone can help me figure out what I should do to make it work for me.

 

The sand is divided into 2 stories. I had sand just in 3/4ths the area of my 20H refugium, but decided a couple months later that it wasn't enough and so put sand in the post-skimmer half of my 20L sump where the overflow to the refugium/DSB is.

 

These are the things I can see as possible problems, or contributers to the time taking so long:

1. The sand was essentially all new - I know it takes a good while for a sand bed to become "established" but am thinking it shouldn't be taking this long

2. I had liverock on top of the sand in both sections, which I decided last week might be causing dead spots so it is no longer there except the small pieces keeping the flow from the sump from making a crater in the sand.

3. The amount of flow going from the refugium/DSB back to the tank might be too high??? I have a pump that is about 500gph, but the water has to go over 4 feet from the floor to the tank so it is losing a considerable amount of that 500. I can go as low as the sump return will let me before it drains the sump dry.

 

Any information and/or suggestions greatly appreciated.

[Highland Reefer]

Are you dosing any carbon sources now?

[treesprite]

Are you dosing any carbon sources now?

No. I'm forever tempted.

 

I set up my xenia fuge (XF) a couple hours ago. Now I have the sump DSB --> 1" PVC --> XF--> 3/4th PVC --> refugium DSB. The smaller pipe slowed down the flow through the fuge DSB a little.

[Origami]

Forrest, the remote DSB's that I've heard of working well have been much deeper than 5". Many that were discussed nearly filled a 5 gallon bucket. Some even nearly filled a 55 gallon aquarium with sand. Here's an RC link that discussed the topic. http://reefcentral.com/forums/showthread.p...threadid=595109

 

If you're not seeing much in the way of denitrification, I would guess that a good part of the sand bed is either aerobic or in transition. Perhaps very little of the sand environment is really in the anaerobic zone needed for denitrification. Going deeper might help. Just a guess.

 

Here's another good link with Anthony Calfo contributing. http://forum.marinedepot.com/Topic20039-13-1.aspx. Hey, you could talk to him in the upcoming meeting about this!

Edited November 8, 2008 by Origami2547

[treesprite]

Forrest, the remote DSB's that I've heard of working well have been much deeper than 5". Many that were discussed nearly filled a 5 gallon bucket. Some even nearly filled a 55 gallon aquarium with sand. Here's an RC link that discussed the topic. http://reefcentral.com/forums/showthread.p...threadid=595109

 

If you're not seeing much in the way of denitrification, I would guess that a good part of the sand bed is either aerobic or in transition. Perhaps very little of the sand environment is really in the anaerobic zone needed for denitrification. Going deeper might help. Just a guess.

 

Here's another good link with Anthony Calfo contributing. http://forum.marinedepot.com/Topic20039-13-1.aspx. Hey, you could talk to him in the upcoming meeting about this!

Anthony Calfo has 3" on WetWeb Media article. http://www.wetwebmedia.com/deepsandbeds.htm . I have seen 3" ither places but can't remember where. This is if not where anything will dig into it. The typical range I have read in various places is 4-6" with anything past 6" having no added benefit. The 5" DSB in my nano kept nitrate at zero with just macros and liverock. I always wonder why psople put sand in HOT refugiums though.

Edited November 9, 2008 by treesprite

[Highland Reefer]

Deep sand beds are divided into three zones. The top aerobic layer which extends down to around 2", the transitional zone at 2-3" and the anaerobic layer which is deeper than the 3" layer. In a 3" sand bed, there is mainly a transitional zone area. If you add more sand, then the size of the anaerobic layer will increase, as well as the number of anaerobic bacteria. A deep sand bed should be at least 4" and preferably 6" in depth. A 6" deep sand bed: 2" aerobic layer; 1" transitional zone; 3" anaerobic layer.

 

The above is just an approximation depending on the size, mix and type of sand you are using.

 

Scientific experiments have shown that when the temperatures range above 80 degrees, that the anaerobic bacteria reproduction rate almost doubles. One argument for keeping your reef temp. at around 80-82 degrees.

 

"Deep Sand Beds", by Dr. Ron Shimek: http://www.ronshimek.com/deep_sand_beds.html

 

In my system, mixing vinegar with kalk has increased the effectiveness of my 6" deep sand bed significantly.

Edited November 9, 2008 by Highland Reefer

[treesprite]

Deep sand beds are divided into three zones. The top aerobic layer which extends down to around 2", the transitional zone at 2-3" and the anaerobic layer which is deeper than the 3" layer. In a 3" sand bed, there is mainly a transitional zone area. If you add more sand, then the size of the anaerobic layer will increase, as well as the number of anaerobic bacteria. A deep sand bed should be at least 4" and preferably 6" in depth. A 6" deep sand bed: 2" aerobic layer; 1" transitional zone; 3" anaerobic layer.

 

The above is just an approximation depending on the size, mix and type of sand you are using.

 

Scientific experiments have shown that when the temperatures range above 80 degrees, that the anaerobic bacteria reproduction rate almost doubles. One argument for keeping your reef temp. at around 80-82 degrees.

 

"Deep Sand Beds", by Dr. Ron Shimek: http://www.ronshimek.com/deep_sand_beds.html

 

In my system, mixing vinegar with kalk has increased the effectiveness of my 6" deep sand bed significantly.

Nice, detailed information - thank you

 

My sand is aragomax regular and sugar fine mixed. My tank temp runs 78 - 80 at night and 79 - 81 during the day, once in a while hitting 82 but not usually.

 

Maybe I could try carbon dosing if I can get really specific doses to keep from screwing up my water. Do you know where I could get very specific dosing/mixing measurements? Is the kalk to compensate for the acidity of the vinegar? I have so far had no need for kalk, but have a container of Kent kalwasser if that would be sufficient for this purpose. I assume I would have to test my water every day.

Edited November 9, 2008 by treesprite

[Coral Hind]

 

In my system, mixing vinegar with kalk has increased the effectiveness of my 6" deep sand bed significantly.

 

How do you know that the vinegar/kalk has improved the DSB significantly?

[Highland Reefer]

 

How do you know that the vinegar/kalk has improved the DSB significantly?

 

 

 

I first started dosing vinegar with the kalk. My nitrates came down from around 80 to around 25. Later I added a deep sand bed refugium. The nitrates dropped to about 2-3. I later stopped dosing vinegar and the nitrates went back up to about 15. I restarted vinegar and they dropped down to about 2-3. I repeated this with the same results. I then added chaeto and it did not grow and nothing happened. I then started dosing iron and now my nitrates are down to zero. My phosphates were reading low, but not low enough to stop the microalgae. I then started using GFO/GAC in a reactor & the microalgae has died off and what is left is dieing. Next, I am going to siphon out the crushed coral (big sink) and put in a 4" sand bed. I have used a 55 gallon Pepsi barrel with 6" of sand. I only have to clean my tank glass about every 1.5 weeks now. I used to have to clean it every other day. When I have to clean my tank glass once per week, I change the GFO. I find that how often I need to clean the glass is a good indicator of where my phosphates are at.

Edited November 9, 2008 by Highland Reefer

[treesprite]

I first started dosing vinegar with the kalk. My nitrates came down from around 80 to around 25. Later I added a deep sand bed refugium. The nitrates dropped to about 2-3. I later stopped dosing vinegar and the nitrates went back up to about 15. I restarted vinegar and they dropped down to about 2-3. I repeated this with the same results. I then added chaeto and it did not grow and nothing happened. I then started dosing iron and now my nitrates are down to zero. My phosphates were reading low, but not low enough to stop the microalgae. I then started using GFO/GAC in a reactor & the microalgae has died off and what is left is dieing. Next, I am going to siphon out the crushed coral (big sink) and put in a 4" sand bed. I have used a 55 gallon Pepsi barrel with 6" of sand. I only have to clean my tank glass about every 1.5 weeks now. I used to have to clean it every other day. When I have to clean my tank glass once per week, I change the GFO. I find that how often I need to clean the glass is a good indicator of where my phosphates are at.

Wow! You worked really hard to figure out how to manage the nitrate. I'm glad you're getting rid of crushed coral. I had it and took it out just over 1.5 years ago and my nitrate was no longer completely through the roof (still high but nowhere near what it was). I didn't know people dosed iron - I'm such a noob. Why wouldn't the chaeto grow? Is it growing now?

[Highland Reefer]

Wow! You worked really hard to figure out how to manage the nitrate. I'm glad you're getting rid of crushed coral. I had it and took it out just over 1.5 years ago and my nitrate was no longer completely through the roof (still high but nowhere near what it was). I didn't know people dosed iron - I'm such a noob. Why wouldn't the chaeto grow? Is it growing now?

 

 

 

Macoalgae uses a lot of iron. You add iron through feeding your fish, but in many systems it is not high enough for the macro to grow properly and is the limiting factor. I am currently dosing about 5 ml. of Fe++ to about 145 gal. of tank water weekly and the macro has doubled in size rapidly.

[Highland Reefer]

Dosing a carbon source in small tanks can be difficult due to the volume of water your are working with. I have not had experience with vodka or sugar.

 

If you wanted to try some vinegar, I would add it to your top-off water at a starting rate of 15 ml of vinegar to one gallon of rodi water. See how that affects the reduction of your nitrates & phosphates. You can slowly increase the dosage as you see fit up to about 30 ml. vinegar to 1 gallon of rodi. Vinegar is a week acid and should not decrease you pH noticably at the above rates. I am dosing vinegar at 75 ml. vinegar per gallon of rodi currently, with no ill effects to my pH. I am not recommending anybody dose at the rates I am at, this is experimental on my part and there are many factors that come into play, which you should be aware of before trying it.

Edited November 9, 2008 by Highland Reefer

[lhcorals]

I have to clean my glass every two days and my Phosphate are 0.

[Highland Reefer]

The test kits we use are not that accurate at the levels of phosphate we are shooting for. You need to keep the phosphate levels below 0.03 ppm. IME your phosphate levels are above 0.02 due to the algae growing on your glass, which is a good indicator (probably better than the kits). If your phosphate levels are below 0.5 (our kits can detect these levels), then a good solution would be to run GFO in a reactor.

Edited November 9, 2008 by Highland Reefer

[lhcorals]

I'm using Pura Complete in my sump.

[Highland Reefer]

You need grannular ferric oxide. Pura Complete is carbon, from what i can gather from this description:

 

-------------------------------------------------------------------------------------------------------------------------------------------------

Magnavore PURA Complete

 

PURA Complete is a blend of GFH; reef type macro-porous select grade bituminous carbon with a high abrasion number and low ash content specifically designed for aqueous phase filtration; and a top grade zeo-sorbent with a high cation exchange capacity for ammonia and heavy metals. This product will remove a very broad range of organic waste like urine, phenols, coloring agents, odors, and proteins; a very broad range of heavy metals like copper, lead, and mercury that accumulate over time from trace quantities found in all fish foods; a very broad range of toxins like medicinal residues, ammonia, formaldehyde and arsenic.

 

It will also remove large quantities of aquarium scum promoters like phosphates and silicates and stress promoters like decomposing food by-products. This is the product of choice for advanced reef, marine, and fresh water hobbyists, combining top performing ingredients, broad spectrum chemical filtration activity, low cost, and a fantastic performance to price ratio. PURA Complete is pH-neutral and is used just like carbon.

 

PURA Complete is ideal for canisters, filter bags, and corner filters. This product has more chemical activity than any other media blend and will not degrade with exposure to high flow rates. Packed hydrated with an induction welded foil seal for freshness, protection, and long shelf life. Used as directed, this product will maintain extremely low phosphate levels and extremely low levels of all aquarium pollutants, allowing the most sensitive aquarium specimens to thrive.

 

-----------------------------------------------------------------------------------------

 

For what it is worth, you can buy granular ferric oxide & granular activated carbon much cheaper at Bulk Reef Supply. If you run these in a reactor it is much more effective. BFS also sells a good quality dual reactor at a good price.

Edited November 9, 2008 by Highland Reefer

[lhcorals]

You need grannular ferric oxide. Pura Complete is carbon, from what i can gather from this description:

 

-------------------------------------------------------------------------------------------------------------------------------------------------

Magnavore PURA Complete

 

PURA Complete is a blend of GFH; reef type macro-porous select grade bituminous carbon with a high abrasion number and low ash content specifically designed for aqueous phase filtration; and a top grade zeo-sorbent with a high cation exchange capacity for ammonia and heavy metals. This product will remove a very broad range of organic waste like urine, phenols, coloring agents, odors, and proteins; a very broad range of heavy metals like copper, lead, and mercury that accumulate over time from trace quantities found in all fish foods; a very broad range of toxins like medicinal residues, ammonia, formaldehyde and arsenic.

 

It will also remove large quantities of aquarium scum promoters like phosphates and silicates and stress promoters like decomposing food by-products. This is the product of choice for advanced reef, marine, and fresh water hobbyists, combining top performing ingredients, broad spectrum chemical filtration activity, low cost, and a fantastic performance to price ratio. PURA Complete is pH-neutral and is used just like carbon.

 

PURA Complete is ideal for canisters, filter bags, and corner filters. This product has more chemical activity than any other media blend and will not degrade with exposure to high flow rates. Packed hydrated with an induction welded foil seal for freshness, protection, and long shelf life. Used as directed, this product will maintain extremely low phosphate levels and extremely low levels of all aquarium pollutants, allowing the most sensitive aquarium specimens to thrive.

 

-----------------------------------------------------------------------------------------

 

For what it is worth, you can buy granular ferric oxide & granular activated carbon much cheaper at Bulk Reef Supply. If you run these in a reactor it is much more effective. BFS also sells a good quality dual reactor at a good price.

 

If you read carefully, the last paragraph states will maintain extremely low Phosphate levels.

[reefmontalvo]

So what test kits do you recommend to detect such low levels? I use salafert I have had great results. I also change my phosphate media and carbon once a month on the month.

[lancer99]

If you read carefully, the last paragraph states will maintain extremely low Phosphate levels.

I agree with Highland Reefer, it sounds like carbon.

 

Far be it from me to suggest that a manufacturer might actually lie in order to sell a product

 

Although meaningless phrases like "specifically designed for aqueous phase filtration" might be a tip-off!

 

-R

[treesprite]

I agree with Highland Reefer, it sounds like carbon.

 

Far be it from me to suggest that a manufacturer might actually lie in order to sell a product

 

Although meaningless phrases like "specifically designed for aqueous phase filtration" might be a tip-off!

 

-R

LOL.

[Highland Reefer]

So what test kits do you recommend to detect such low levels? I use Salifert I have had great results. I also change my phosphate media and carbon once a month on the month.

 

The test kits used to measure phosphates down in the range of 0.02 are fairly expensive. I have used the API, which will let you know if your levels are quite high, but are worthless down at the lower levels. I use the Salifert & it is ok, as long as you get readings of zero.

 

The best: Photometers are pricey @ over $200.00. I use the Hach PO4-19, which will run you about $90.00 including shipping. The refills are only about $20.00/100 tests.

 

I still think that judging your phosphates by the amount of scrapping of algae on your glass is the best test kit. If you have to clean your glass more than once per week, then your phosphates are too high. Using this method with the Salifert Kit works great and is the most economical approach.

 

If the phosphates get too high then you need to cut back on your feeding. If that does not work, then you have to adjust your GFO: add more flow or more GFO or replace it. If they get too low (no scrapping for more than 1.5 weeks), then you need the reverse. The GFO reactor is great for this fine tuning.

Edited November 10, 2008 by Highland Reefer

[sen5241b]

I've heard its important to have something that can stir the sand in a DSB such as Nassarius snails or bristleworms.

[Dtip]

Calfo is talking about regular sand beds in tank or in a refugium in that article I think. When talking about RDSBs, everything I've heard directly from him and others has suggested far deeper: nearly filling a 5gal is the standard application. A DSB in a fuge may help, but it's not going to get those deep, low oxygen cryptic zones you need to really eat away at nitrates, and it can't work like the standard RDSB, which basically puts all the focus on water flow that does not allow any light or debris to settle on the surface of the sand.

[Rascal]

I agree Highland Reefer and others on the amount of sand - the more the better for nitrate reduction. I have a 4-6" DSB in my display, but I also have a 8-10" DSB in a 55 gallon container. IMO you want a diversity of little scavenger type critters to get the most out of it. From nassarius snails to worms of all types (bristle, spaghetti, whatever), and pods of all types. My DSB doubles as a fuge so I also have some rubble and chaeto in there - lots of stuff. I find it good practice to periodically add some new live rock and/or live sand to "re-charge" the critter population.

 

My sand beds will process nitrates down to zero (undetectable), but IME nuisance algae will out-compete the anaerobic bacteria if other conditions are right. Not sure if out-compete is the right term, but what I mean is that algae will utilize available nitrates before they can be broken down by bacteria if there is enough light and phosphate around for the algae to thrive. I think that is why for me the key to keeping nuisance algae at bay has always been to control phosphates. GFO has always been my weapon of choice but I am currently experimenting with mixed C dosing (Vodka, sugar and vinegar) with pretty dramatic results. More on that in other thread perhaps . . .

[Highland Reefer]

I've heard its important to have something that can stir the sand in a DSB such as Nassarius snails or bristle worms.

 

Stirring up a deep sand bed can have adverse affects, like releasing to much sulfur, which is toxic. So, I would be cautious as to what you add in that respect. Certainly, adding things that will eat the top debris will not be harmful. I would think that bristle worms & certain snails would be ok. Things like conk snails, I would not add.

Edited November 10, 2008 by Highland Reefer