Are you concerned about DOC?

[p1u5h13r4m24]

The hobby has changed drastically over the past 20-30 years. In the past it was simple; we used t5/ metal halide and 10% weekly water changes. Today we have tons of new types of filtration, additives such as GFOs, and trace elements/monitoring such as ICP and moonshiners.

I feel like today there are many more people who are skipping water changes. There are many new products that can allow us to do that, but are we missing something?

We know that there are some good and bad effects of DOC. At what point do you determine your DOC may be getting too high? Can your DOC be too low? Lastly how do you determine if it’s too high or too low?

 

[Mr. Mojo Rising]

I learned so much about doc's as a seahorse keeper, I learned very quickly that elevated doc's harm and can quickly kill seahorses.

So I started the research, and now firmly believe that docs are detrimental to reefs and to our reef tanks, and docs can kill some delicate livestock. Removing docs from the water is now my major concern and priority as a reefer, I find this shift in my belief system has worked well for me.

https://reefbuilders.com/2024/06/21...hy-reef-tank-heres-a-new-method-to-manage-it/

 

[p1u5h13r4m24]

I recently cut back on my water changes because I dose all for reef and kalkwasser. Just yesterday I decided to put a container of fresh mixed saltwater next to a container of tank water. I used white cool whip containers so it was easier to see the yellow tint. I was surprised to see the tank water really was much more yellow. So I’m going to do a series of 5% water changes every 2-3 days until it clears up. My biggest concern is dropping nutrients too far. So do I over feed and add DOC to raise nutrients just so k can do a water change and remove them? It seems like a catch 22

 

[Randy Holmes-Farley Verified Community Expert]

Dissolved organic compounds are an extremely diverse set of chemicals. They range from desirable to highly toxic. It is unfortunate that we cannot (at the moment) quantify individual types.

Because some are toxins or are otherwise undesirable, I do recommend treatments such as water changes, skimming, and GAC. Other useful products include Purigen and poly filters.

 

[p1u5h13r4m24]

I read through your article so I understand there are benefits, as well. I believe you compared it to a bucket of rocks. Some good alloys some bad. I prefer to do water changes because every time I’ve used GAC I seem to somehow get reverse effects from it.
I’m really trying to see what type of plan people follow to monitor and what they do to make adjustments. How to determine we should begin to lower it . I guess I’m geared more towards the hobbyist who are keeping acropora over a year period without water changes.

 

[p1u5h13r4m24]

I learned so much about doc's as a seahorse keeper, I learned very quickly that elevated doc's harm and can quickly kill seahorses.

So I started the research, and now firmly believe that docs are detrimental to reefs and to our reef tanks, and docs can kill some delicate livestock. Removing docs from the water is now my major concern and priority as a reefer, I find this shift in my belief system has worked well for me.

https://reefbuilders.com/2024/06/21...hy-reef-tank-heres-a-new-method-to-manage-it/

This is a good article. One of the ways they mention is best to remove doc is by growing sponge. Luckily for me i have quite a bit growing in my system already. However im going to start doing some waterchanges

 

[Randy Holmes-Farley Verified Community Expert]

One of the ways they mention is best to remove doc is by growing sponge. Luckily for me i have quite a bit growing in my system already. However im going to start doing some waterchanges

I don’t think there is any evidence supporting that sponge claim in terms of usefully lowering doc in a typical reef tank.

 

[p1u5h13r4m24]

I was referring to this part of the article. But I’m unsure if there are any studies of it within our reef tank
“In nature, sponges complete the carbon cycle by uptaking massive amounts of DOC and then converting that dissolved carbon into particulate organic carbon (POC), which is shed into the water column and eventually acts as food for corals. On healthy reefs, “sponge looping” effectively recycles excess DOC into additional food for the corals on top of the picoplankton they’re already consuming.“

 

[Bohemian Waxwing]

I will leave the science to our more adept members like @Lasse , @Miami Reef and Randy.

When I got into the hobby I was taught by a very successful reefer that water changes are vital and I’ve since stuck to that with good results.

When I was in Fish and Wildlife, we even used the same concept to deal with polluted or highly stocked bodies of water, as the old saying goes “dilution is the solution to pollution”.

 

[Pistondog]

The hobby has changed drastically over the past 20-30 years. In the past it was simple; we used t5/ metal halide and 10% weekly water changes. Today we have tons of new types of filtration, additives such as GFOs, and trace elements/monitoring such as ICP and moonshiners.

I feel like today there are many more people who are skipping water changes. There are many new products that can allow us to do that, but are we missing something?

We know that there are some good and bad effects of DOC. At what point do you determine your DOC may be getting too high? Can your DOC be too low? Lastly how do you determine if it’s too high or too low?

Docs seem like a likely important element we are ignoring.
More research and interest can help us understand its ramifications.

 

[Randy Holmes-Farley Verified Community Expert]

I was referring to this part of the article. But I’m unsure if there are any studies of it within our reef tank
“In nature, sponges complete the carbon cycle by uptaking massive amounts of DOC and then converting that dissolved carbon into particulate organic carbon (POC), which is shed into the water column and eventually acts as food for corals. On healthy reefs, “sponge looping” effectively recycles excess DOC into additional food for the corals on top of the picoplankton they’re already consuming.“

Right. I understood. Don’t accept everything you read.

It’s an unsupported assertion that it is an important factor in a typical reef tank. It may or may not be true, but it seems unlikely to be true to me. I’m not asking anyone to accept my expectation, but to be skeptical of claims with no supporting data at all.

In nature, volcanos destroy a lot of corals. Does that mean it happens in reef tanks?

 

[Ryan - Serious Reefs]

The hobby has changed drastically over the past 20-30 years. In the past it was simple; we used t5/ metal halide and 10% weekly water changes. Today we have tons of new types of filtration, additives such as GFOs, and trace elements/monitoring such as ICP and moonshiners.

I feel like today there are many more people who are skipping water changes. There are many new products that can allow us to do that, but are we missing something?

We know that there are some good and bad effects of DOC. At what point do you determine your DOC may be getting too high? Can your DOC be too low? Lastly how do you determine if it’s too high or too low?

This is a deviation from your question and just my personal experience, but I really bought into the 'no water change' approach around 2017. I wanted to believe it was the evolution of reefing, but in the end, I spent more time chasing test kits and dosing bottles than it was worth. Any time I slipped up or got lazy with the mail in testing, there were immediate signs of trouble in the tank. I always felt like there were things the ICP wasn't testing for, like petroleum products, lotions, fragrances, aerosols, soap, and anything that could be on our hands or air.

The emergence of the DOC test, and your question, highlight the rabbit hole we tumble down in search of the perfect balance in a no-water-change environment. But ultimately, I stopped avoiding water changes and made them easier with AWC. The results were more stable, easier, and cheaper in the end. This is a journey that many of my peers have gone down as well. Excited about the opportunity but the ultimate lesson is "hey these WC are more valuable than I thought." Almost like a phase of reefing that we all go through :)

This is an example of an SPS tank I ran with zero filtration or gear, relying solely on AWC. Worrying about ICP/DOC/Unknowns just wasn’t a thing. Easiest tank of my life even though the coral density to water volume should have made it one of the most challenging. "

I'd encourage you to follow what interests you, implement and learn. Just don't get stock trying to jam the square peg in the round hole if it turns out to not be right for you.

 

[p1u5h13r4m24]

This is a devotion from your question and just my personal experience, but I really bought into the 'no water change' approach around 2017. I wanted to believe it was the evolution of reefing, but in the end, I spent more time chasing test kits and dosing bottles than it was worth. Any time I slipped up or got lazy with the mail in testing, there were immediate signs of trouble in the tank. I always felt like there were things the ICP wasn't testing for, like petroleum products, lotions, fragrances, aerosols, soap, and anything that could be on our hands or air.

The emergence of the DOC test, and your question, highlight the rabbit hole we tumble down in search of the perfect balance in a no-water-change environment. But ultimately, I stopped avoiding water changes and made them easier with AWC. The results were more stable, easier, and cheaper in the end. This is a journey that many of my peers have gone down as well. Excited about the opportunity but the ultimate lesson is "hey these WC are more valuable than I thought." Almost like a phase of reefing that we all go through :)

This is an example of an SPS tank I ran with zero filtration or gear, relying solely on AWC. Worrying about ICP/DOC/Unknowns just wasn’t a thing. Easiest tank of my life even though the coral density to water volume should have made it one of the most challenging. "

I'd encourage you to follow what interests you, implement and learn. Just don't get stock trying to jam the square peg in the round hole if it turns out to not be right for you.

To be fair I 100% agree with this. Although the evolution of reef keeping has made things easier, it has made them a bit more confusing for people. I still do water changes just not as frequent because I dose all for reef. I believe it can act as a carbon source so my nutrients usually run on the low side and it limits the amount of water changes I can do

 

[Ryan - Serious Reefs]

Docs seem like a likely important element we are ignoring.
More research and interest can help us understand its ramifications.

I won’t claim to know the answer, but I strongly suspect that in a small closed system, with food, fish waste, and algae entering and decaying daily, it's unlikely that 'valuable DOC' will be severely deficient. More likely, it will be pollutive in nature. At least, this is probably the case for the majority, with a few inevitable outliers.

That said, we won’t know for sure unless trailblazers are willing to challenge common thought. As someone who has spent a lot of time trailblazing, just know they’re the first to get shot in the back. It’s a low-percentage, exploratory path.

 

[p1u5h13r4m24]

I won’t claim to know the answer, but I strongly suspect that in a small closed system, with food, fish waste, and algae entering and decaying daily, it's unlikely that 'valuable DOC' will be severely deficient. More likely, it will be pollutive in nature. At least, this is probably the case for the majority, with a few inevitable outliers.

That said, we won’t know for sure unless trailblazers are willing to challenge common thought. As someone who has spent a lot of time trailblazing, just know they’re the first to get shot in the back. It’s a low-percentage, exploratory path.

Thank you for your input! Honored to have you on the thread!
I’m hoping to one day see a type of sensor or test that we could use as a means of measurement for DOC. This way we can more accurately determine at what levels problems can arise.

 

[Randy Holmes-Farley Verified Community Expert]

I’m hoping to one day see a type of sensor or test that we could use as a means of measurement for DOC. This way we can more accurately determine at what levels problems can arise.

FWIW, at least one company I know of is trying to develop more meaningful tests than just doc. It won’t be an at home test, but it may allow one to discriminate. DOC can be tested now, but it is a send out test.

The analogy is that doc is akin to salinity. Just a total measurement if all sorts of things. An individual test for calcium can be much more enlightening, as might, say, a test that can detect the common toxins likely to be produced in reef tanks (such as “red tide” sorts of toxins).

 

[p1u5h13r4m24]

FWIW, at least one company I know of is trying to develop more meaningful tests than just doc. It won’t be an at home test, but it may allow one to discriminate. DOC can be tested now, but it is a send out test.

The analogy is that doc is akin to salinity. Just a total measurement if all sorts of things. An individual test for calcium can be much more enlightening, as might, say, a test that can detect the common toxins likely to be produced in reef tanks (such as “red tide” sorts of toxins).

I’m aware of the company. I have thought about getting a sample out of curiosity. I know the original method I found years ago was to use a white container to put the tank water in and compare that to fresh mixed saltwater. If there is a yellow tint then DOC would be high. I know it wouldn’t be a pin point test for toxins, but I was thinking a light sensor type test like hanna could give us a measurement. Sort of just a measurement of the yellow hue. Again it wouldn’t pinpoint good or bad elements but a general idea. Maybe too much; maybe useful ?

 

[Ryan - Serious Reefs]

To be fair I 100% agree with this. Although the evolution of reef keeping has made things easier, it has made them a bit more confusing for people. I still do water changes just not as frequent because I dose all for reef. I believe it can act as a carbon source so my nutrients usually run on the low side and it limits the amount of water changes I can do

The sheer number of options these days causes a lot of confusion. One thing that often gets lost in translation is that most reasonably good options will work for 12 months, the better ones 24 months, and only a select few will produce better than 50% success rates for 36+ months. The ones that didn’t work? Those people are no longer around to share their experience.

Part of why I like WC is it takes out the mad scientist element and replaces it with an option that just works. In most cases it works on things most reefers have never even considered.

• Foods: Nutrients (N/P) are obvious, DOC what you are asking about today. Consider the food, it's not just nitrogen and phosphorus, preservatives, elements, or other additives are accumulating.
• Element additives: Water changes help manage the inevitable trace element imbalances of our additives. None of them are perfectly matched to our tank’s uptake so over time some elements will rise/deplete. Coupled with a good additive system, WC/dilution will slow down and likely prevent dangerously high or low levels of most elements.
• Unintended contaminants: Anything aerosolized in the home or introduced via our hands. Some could be immediately toxic and others just build up over time and most are not going to show up on a ICP test kit.

I recently released a video that demonstrates what water changes are actually doing in the tank. 26:00 is the time stamp. It's a SR members video but here is link for a free month so you can see it without costing anything.

 

[Randy Holmes-Farley Verified Community Expert]

Sort of just a measurement of the yellow hue. Again it wouldn’t pinpoint good or bad elements but a general idea. Maybe too much; maybe useful ?

Many folks do such tests, as have I. But some methods, such as ozone, reduce yellowing without doing much for total doc.

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Two digital photographs of a plastic bar taken through four feet of aquarium water. The bar on the left was taken before using ozone, and the bar on the right was taken after two weeks on ozone. The numbers were written onto the bar with marking pens. All camera settings were identical.​

 

[pooootiqe]

This is a deviation from your question and just my personal experience, but I really bought into the 'no water change' approach around 2017. I wanted to believe it was the evolution of reefing, but in the end, I spent more time chasing test kits and dosing bottles than it was worth. Any time I slipped up or got lazy with the mail in testing, there were immediate signs of trouble in the tank. I always felt like there were things the ICP wasn't testing for, like petroleum products, lotions, fragrances, aerosols, soap, and anything that could be on our hands or air.

The emergence of the DOC test, and your question, highlight the rabbit hole we tumble down in search of the perfect balance in a no-water-change environment. But ultimately, I stopped avoiding water changes and made them easier with AWC. The results were more stable, easier, and cheaper in the end. This is a journey that many of my peers have gone down as well. Excited about the opportunity but the ultimate lesson is "hey these WC are more valuable than I thought." Almost like a phase of reefing that we all go through :)

This is an example of an SPS tank I ran with zero filtration or gear, relying solely on AWC. Worrying about ICP/DOC/Unknowns just wasn’t a thing. Easiest tank of my life even though the coral density to water volume should have made it one of the most challenging. "

I'd encourage you to follow what interests you, implement and learn. Just don't get stock trying to jam the square peg in the round hole if it turns out to not be right for you.

Just wanna say your “perfect is the enemy of great” might be the greatest reefing videos I’ve ever seen. I always go back to them to remind myself of the foundations every time I’m tempted by some fancy techniques or gadgets ;)