Are the risks of having a deep sandbed exaggerated?

[vlangel]

I have a deep sand bed on my first attempt. I disturbed it once and got quite a surprise ie found out what lurks below, kind of like dune. So never did it again. Now I could not clean it if I wanted to. Its 30 years old never an issue. Funny no bristle worms but in my other tank its like I am farming them

Am I understanding you correctly; your current DSB is 30 years old? Whoa that is the oldest I have heard of!
So why do you think there are no bristleworms? That is interesting because my tank used to have bristleworms but I have not seen any for a couple of years and I haven't changed the way I feed. In fact if anything I feed more now.

 

[vlangel]

I’m not claiming denitrification does not happen in SubSea’s tank. I just want folks to recognize that no tank can prove it without a before and after comparison when adding or removing a deep sand bed.

Just like any husbandry practice and any aspect of that tank, it does not mean the practice contributed to the result, maybe the result happened in spite of the practice.

OK, gotcha! That's fair. We just don't get much data comparing apples and apples. I know anytime that I tore out a deep sandbed, I was starting a new tank which is not apples and apples. I have read a few folks who tore out SSB and then had trouble that they had never had before but don't recall anyone tearing out a DSB in favor of a SSB or BB.

 

[56longroof]

Any yet, there are others without a DSB who also need to dose N. All it means is that demand is outstripping supply of N, and in a mature tank with lots of growth, that certainly can happen. I think we just need to be careful about what a single data point says.

What other methods are being used? Does it require a piece of equipment or dosing something? The simplicity of a DSB is the major selling point for me.

 

[vlangel]

What other methods are being used? Does it require a piece of equipment or dosing something? The simplicity of a DSB is the major selling point for me.

Plus, if you like sand, you get it without having to go through the rigor of vacuuming it regularly!

 

[DeSoDo]

I'm still new at reef tanks, but I have a 5" sandbed because I knew for a fact that I wanted a pistol shrimp and ywg. The shrimp has rearranged my entire tank the entire 6 months I've had it up and running. No issues other than cloudiness of the water because it's constantly digging, sifting and moving it around.

 

[Freenow54]

Am I understanding you correctly; your current DSB is 30 years old? Whoa that is the oldest I have heard of!
So why do you think there are no bristleworms? That is interesting because my tank used to have bristleworms but I have not seen any for a couple of years and I haven't changed the way I feed. In fact if anyt

hing I feed more now.

No idea. My new tank is unbelievably full of them . I feed with Mysis shrimp flakes. algae pellets , and nori. The other tank only has one fish, a nasty clown but full of mushrooms the food has fish meal byproducts as well ? Bad picture but these ( in pink are just new in the last couple of days

 

[vlangel]

I'm still new at reef tanks, but I have a 5" sandbed because I knew for a fact that I wanted a pistol shrimp and ywg. The shrimp has rearranged my entire tank the entire 6 months I've had it up and running. No issues other than cloudiness of the water because it's constantly digging, sifting and moving it around.

I am not sure with your industrious shrimp if you will get the benefits of denitrification. No doubt the shrimp is worth it however.

 

[Twink_w_a_Reef]

I think that the issue with deep sand beds is when the deep sand bed is disturbed it kills off anaerobic bacteria that live in it and that’s what messes things up

 

[DeSoDo]

I think that the issue with deep sand beds is when the deep sand bed is disturbed it kills off anaerobic bacteria that live in it and that’s what messes things up

Oh, I misunderstood then. I was only thinking about the disruptions causing gas buildup issues.

 

[Randy Holmes-Farley Verified Community Expert]

What other methods are being used? Does it require a piece of equipment or dosing something? The simplicity of a DSB is the major selling point for me.

I cannot answer about all the tanks, but there are 74 pages of discussion by folks dosing ammonia to supply N in the thread below, and I assume they use all sorts of different husbandry techniques:

https://www.reef2reef.com/threads/diy-ammonia-dosing-for-low-nitrate-systems.987087/

 

[sgdnycct]

That is true Randy but most who are dosing nitrate additives are using protein skimmers, reactors, vodka dosing or some other sort of method that requires fairly regular maintenance. If the DSB does indeed reduce nitrates, it denitrifies without regular maintenance. Maybe my macroalgae and mature coral colonies are what limits my nitrates in fairness to your thoughts.

However, I lean toward a DSB contributing to denitrification because of my good friend who had a large very heavily stocked predator FOWLR tank with a 23 year old DSB. In a 250 gallon tank she only did a 20-25 gallon WC once a month. I serviced this tank for over a decade and all parameters were good. She had multiple big puffers, triggers, tangs and an emperor angel the size of a dinner platter. The angel was really too big for the tank but with it being over 20 years old we were afraid to rehome it. But with the food she put in that tank daily, the nitrates should have been off the scale and they werent.
And hers was not the only tank I witnessed this while I worked for the lfs. Hers was the longest because she and I remained friends even after the lfs closed.

That is my experience as well. My focus is fish and I feed heavy. Between LR+Ref+DSB my parameters are great. PO and NO at 0.

 

[vlangel]

That is my experience as well. My focus is fish and I feed heavy. Between LR+Ref+DSB my parameters are great. PO and NO at 0.

I feel rather stupid: LR+Ref+DSB. Live rock and deep sandbed I know. What is Ref?

 

[vlangel]

I cannot answer about all the tanks, but there are 74 pages of discussion by folks dosing ammonia to supply N in the thread below, and I assume they use all sorts of different husbandry techniques:

https://www.reef2reef.com/threads/diy-ammonia-dosing-for-low-nitrate-systems.987087/

I need to read through that thread some time just to learn the different methods of nutrients export.

 

[Randy Holmes-Farley Verified Community Expert]

Between LR+Ref+DSB my parameters are great. PO and NO at 0

This is exactly my point. This example does not support that a dsb is driving nitrate to zero, assuming Ref means refugium. It doesn’t refute it either, but…

A refugium plus a dsb?

That leads to several comments.

1. Deep sand beds do not remove phosphate by the mechanism they remove nitrate. Thus, any removal of phosphate is happening some other way.

2. The refugium is likely a part of the phosphate removal. Maybe most or all of it. But refugia remove both N and P, and one could well expect that a refugium driving phosphate to zero might well also drive nitrate to zero, leaving little for the dsb.

3. 0 ppm nitrate and phosphate may not be ideal for corals. I get that your focus is fish and you do not mention corals, but zero isn’t usually thought best.

 

[vlangel]

This is exactly my point. This example does not support that a dsb is driving nitrate to zero, assuming Ref means refugium. It doesn’t refute it either, but…

OK, thank you. Doh, I just couldn't figure out Ref, LOL.

 

[Subsea]

What other methods are being used? Does it require a piece of equipment or dosing something? The simplicity of a DSB is the major selling point for me.

While I have never used them, I see much advantages for ATS. Disadvantages include initial cost and maintenance to harvest algae as well as small electrical cost for light.

I used a DSB with a Jaubert plenum for 20 years. Maintenance included light stirring of sand bed surface which creating an immediate feeding response. After introduction of Melanurus Wrasse, biodiversity in sandbed decreased and less TLC on my part resulting in system degradation (maybe “old tank syndrome), prompted a dramatic change in biofiltration.

Focus changed from nutrient export to nutrient recycling.

So, 5 years ago, I removed, over a 2 week period, substrate in 75G display tank from 5” to 2” and modified plenum to flow water up thru substrate. At the same time, I turned out the lights in 30G algae/mud refugium and added diver collected live rock.

 

[CoastalTownLayabout]

Incremental wins vlangel. In 20 years the needle has glacially shifted from ticking time bomb to neutral, possibly useless method. In another 20 years we may be able implant a chip deep in the sandbed to finally adjudicate on one of the great mysteries of reefing:)

 

[sgdnycct]

This is exactly my point. This example does not support that a dsb is driving nitrate to zero, assuming Ref means refugium. It doesn’t refute it either, but…

A refugium plus a dsb?

That leads to several comments.

1. Deep sand beds do not remove phosphate by the mechanism they remove nitrate. Thus, any removal of phosphate is happening some other way.

2. The refugium is likely a part of the phosphate removal. Maybe most or all of it. But refugia remove both N and P, and one could well expect that a refugium driving phosphate to zero might well also drive nitrate to zero, leaving little for the dsb.

3. 0 ppm nitrate and phosphate may not be ideal for corals. I get that your focus is fish and you do not mention corals, but zero isn’t usually thought best.

Yes Ref is refugium.

Absolutely! Just like one doesn’t depend on ONLY a protein skimmer or ONLY a refugium. We all use multiple angles to manage the system. For me a refugium + DSB + LR. Others use a refugium + protein skimmer and the combinations go on. I don’t know if anyone uses only an DSB. People use a combination of components to maintain a their system based on knowledge, experience and what they’ve been taught.

So I’m not sure what you are saying here. Is it that the DSB does nothing or only part of it?

 

[CHSUB]

Just like any husbandry practice and any aspect of that tank, it does not mean the practice contributed to the result, maybe the result happened in spite of the practice.

Yes, hopefully I can use this quote in other discussions…thanks.

 

[VintageReefer]

If I had to categorize everything,

3-5” sandbed
Live rock
ATS
Dedicated cryptic zone with sponge

I have no media to replace. The setup is silent and natural. It runs essentially for free, except for 10ish watts of power for the scrubber setup. I open the scrubber lid once every 7-10 days, grab a handful of algae and throw it out. Thats my maintenance