Testing for dissolved organics in a seahorse tank.

[rayjay]

I'm lost in some of this conversation, not understanding some terms and relationships but welcome any discussion that may lead to a reasonable test. However, for the seahorse hobby, terms like high or low may not mean much as what is low in REEF tank terms would be high in seahorse tank terms.
I think any test kit developed would have to lead to practical measurable limits determined by experimentation in the hobby. Until we can test for it, we can't determine the safe range, but hopefully we can come up with a NUMBER to give hobbyists to go by rather than high or low or something in between that will be construed differently by different people depending on what kind of tank they are keeping.
I don't believe that increasing DO levels in a reef tank are as severe a problem as in a seahorse tank, as reef inhabitants are not nearly as susceptible to nasty bacteria as the low immune seahorses are.
A question I still don't know is, are ALL DO's carbon or are there also DO's that WON'T be measured by a test for dissolved organic carbon?

 

[ISpeakForTheSeas]

I'm lost in some of this conversation, not understanding some terms and relationships but welcome any discussion that may lead to a reasonable test. However, for the seahorse hobby, terms like high or low may not mean much as what is low in REEF tank terms would be high in seahorse tank terms.
I think any test kit developed would have to lead to practical measurable limits determined by experimentation in the hobby. Until we can test for it, we can't determine the safe range, but hopefully we can come up with a NUMBER to give hobbyists to go by rather than high or low or something in between that will be construed differently by different people depending on what kind of tank they are keeping.
I don't believe that increasing DO levels in a reef tank are as severe a problem as in a seahorse tank, as reef inhabitants are not nearly as susceptible to nasty bacteria as the low immune seahorses are.
A question I still don't know is, are ALL DO's carbon or are there also DO's that WON'T be measured by a test for dissolved organic carbon?

I'm sure someone more qualified will answer this eventually (hopefully with more info), but there is also Dissolved Organic Phosphorus and Dissolved Organic Nitrogen.

 

[Dan_P]

Would it be possible to calculate approximately the DON trough ammonia released from the sand bed @Dan_P

What experiment did you have in mind? Rinsed aquarium sand (to minimize particulate organic nitrogen from being digested) mixed with a known amount of aquarium water?

 

[sixty_reefer]

What experiment did you have in mind? Rinsed aquarium sand (to minimize particulate organic nitrogen from being digested) mixed with a known amount of aquarium water?

Along those lines, I read somewhere that we could calculate organic matter by the ammonia released.
I was thinking similar to your idea, I was thinking aquarium sand without water and topped up with 0ppm saltwater and see if we could calculate something from the ammonia released from it during a 24 hour period.
this could indicate how much organics could be trapped in the sand bed, imo there’s were most nutrients get trapped in our systems. Just throwing ideas you are the expert in testing

ideally a reagent that could dissolve all the organics in the sand bed, like in the soil test kit that I’ve shared would be more precise at calculating organic nitrogen and phosphorus before they got release into the water column. Then use a similar method like they use to calculate the pound per hectare template to calculate ppm per inch of sand or similar.

here’s the link if you want to look at

Agricultural Soil Testing Kits - Soil - Products

Leading manufacturer of water quality testing products including instruments, test strips, kits, reagents, and sampling equipment.

lamotte.com

 

[Dan_P]

Until we can test for it, we can't determine the safe range, but hopefully we can come up with a NUMBER to give hobbyists to go by rather than high or low or something in between that will be construed differently by different people depending on what kind of tank they are keeping.

A quick question, if organic carbon is not being measured, how do we know that high organic levels is an issue for seahorses? Who made came up with that conjecture?

 

[Dan_P]

Along those lines, I read somewhere that we could calculate organic matter by the ammonia released.
I was thinking similar to your idea, I was thinking aquarium sand without water and topped up with 0ppm saltwater and see if we could calculate something from the ammonia released from it during a 24 hour period.
this could indicate how much organics could be trapped in the sand bed, imo there’s were most nutrients get trapped in our systems. Just throwing ideas you are the expert in testing

ideally a reagent that could dissolve all the organics in the sand bed, like in the soil test kit that I’ve shared would be more precise at calculating organic nitrogen and phosphorus before they got release into the water column. Then use a similar method like they use to calculate the pound per hectare template to calculate ppm per inch of sand or similar.

here’s the link if you want to look at

Agricultural Soil Testing Kits - Soil - Products

Leading manufacturer of water quality testing products including instruments, test strips, kits, reagents, and sampling equipment.

lamotte.com

Another way to use bacteria to tells how much digestible stuff is around is oxygen demand. @taricha used this in some of his investigations along with total phosphorous and total nitrogen test kits. I don’t remember all the details so when his schedule permits, he can bring us up to date.

Biological oxygen demand (BOD)is a standard water purity test that gives you a feeling for how much digestible organics there are in the water. It is a cheap test, technically fussier than hobby kits but within the range of anyone who can follow directions. The chemical analysis for organic carbon, chemical oxygen demand (COD), is correlated with BOD. Maybe the seahorse community just needs to start tracking BOD.

 

[rayjay]

Along those lines, I read somewhere that we could calculate organic matter by the ammonia released.
I was thinking similar to your idea, I was thinking aquarium sand without water and topped up with 0ppm saltwater and see if we could calculate something from the ammonia released from it during a 24 hour period.
this could indicate how much organics could be trapped in the sand bed, imo there’s were most nutrients get trapped in our systems. Just throwing ideas you are the expert in testing

ideally a reagent that could dissolve all the organics in the sand bed, like in the soil test kit that I’ve shared would be more precise at calculating organic nitrogen and phosphorus before they got release into the water column. Then use a similar method like they use to calculate the pound per hectare template to calculate ppm per inch of sand or similar.

First, a LOT of seahorse tanks do NOT have sandbed/substrate. Bare bottom makes it a LOT easier than substrate to keep free of uneaten food and detritus.
Seahorses are a very DIRTY feeding animal. First, they only pick the choice (in their eyes) pieces to snick up, leaving the rest to contaminate. Then Upon snicking the piece, they masticate it, passing a lot of micro particles out through the gills, further contaminating the water.

 

[rayjay]

A quick question, if organic carbon is not being measured, how do we know that high organic levels is an issue for seahorses? Who made came up with that conjecture?

To the best of my knowledge Dan, it came from the commercial seahorse aquaculture industry overseas. When looking for reasons for seahorse mortalities and normal nutrient testing and whatever else they were doing in the lab didn't indicate a problem, someone picked on DO to lab test and over some period of time they determined that higher DO led to the problems but if DO was kept from increasing they didn't have problems. When DO levels increased it was noted that nasty bacteria levels also increased along with pathogens such as ciliates that also kill so many seahorses via gill infestation.
Unfortunately, hobbyists can't afford to pay for lab testing all the time.
I don't know if they did some kind of Dissolved Organics test or a Dissolve Organic Carbon test. It seemed to have been about a decade ago when this knowledge hit the hobby scene and since then the recommendation is to use a skimmer rated a minimum of 2X tank volume but larger is better. Also, it takes excellent filtration, tank husbandry and large water changes more frequently, cleaning anything that traps uneaten food and detritus BEFORE decomposition sets in and increased nutrient and DO levels in the tank.
So, if you still end up down the road with say a nasty bacterial infection, you then are advised to not just treat the seahorse in a hospital tank but revise your tank situation to be more extreme so less of a chance of increasing DO.

 

[sixty_reefer]

Another way to use bacteria to tells how much digestible stuff is around is oxygen demand. @taricha used this in some of his investigations along with total phosphorous and total nitrogen test kits. I don’t remember all the details so when his schedule permits, he can bring us up to date.

Biological oxygen demand (BOD)is a standard water purity test that gives you a feeling for how much digestible organics there are in the water. It is a cheap test, technically fussier than hobby kits but within the range of anyone who can follow directions. The chemical analysis for organic carbon, chemical oxygen demand (COD), is correlated with BOD. Maybe the seahorse community just needs to start tracking BOD.

Hopefully he can Give us his thoughts soon, I’ve seen that test, seems a good technique.

what do you make out of this Dan?
I couldn’t find my ammonia test kit to verify if the previously idea was possible, instead I’ve been playing around with no3 test kit and it seems that my reagent can dissolve organics trapped in the sand bed.

if it wasn’t able to dissolve organics the sample with sand and RO should look like the test on the right that is RO only.
The water and the sand seem to have the same ppm concentration also. Any thoughts?

edit: my test kit work on fresh water also.

 

[rayjay]

Not sure where you are going with that. The organics are ALREADY dissolved, that's why the name dissolved organics.
You can take a sample of water high in DO and test for ammonia, nitrite and nitrate and get all zero or near to it readings.

 

[sixty_reefer]

Not sure where you are going with that. The organics are ALREADY dissolved, that's why the name dissolved organics.
You can take a sample of water high in DO and test for ammonia, nitrite and nitrate and get all zero or near to it readings.

There’s no aquarium water in the middle sample just sand and RO water, if it wasn’t dissolving the organics the water should of been clear like the test on the right. My first reagent is a powder and the second reagent for colour is a liquid, I believe this test kit may be working similar to the soil test kit we’re all organics are being dissolved with the first reagent. I use JBL testing lab

 

[Dan_P]

To the best of my knowledge Dan, it came from the commercial seahorse aquaculture industry overseas. When looking for reasons for seahorse mortalities and normal nutrient testing and whatever else they were doing in the lab didn't indicate a problem, someone picked on DO to lab test and over some period of time they determined that higher DO led to the problems but if DO was kept from increasing they didn't have problems. When DO levels increased it was noted that nasty bacteria levels also increased along with pathogens such as ciliates that also kill so many seahorses via gill infestation.
Unfortunately, hobbyists can't afford to pay for lab testing all the time.
I don't know if they did some kind of Dissolved Organics test or a Dissolve Organic Carbon test. It seemed to have been about a decade ago when this knowledge hit the hobby scene and since then the recommendation is to use a skimmer rated a minimum of 2X tank volume but larger is better. Also, it takes excellent filtration, tank husbandry and large water changes more frequently, cleaning anything that traps uneaten food and detritus BEFORE decomposition sets in and increased nutrient and DO levels in the tank.
So, if you still end up down the road with say a nasty bacterial infection, you then are advised to not just treat the seahorse in a hospital tank but revise your tank situation to be more extreme so less of a chance of increasing DO.

Great information. Did they publish numbers that might help us or was it “more is bad less is good” kinda thing? If “more“ means many ppm organics, biological oxygen demand might be the answer, though how will we test the idea?

 

[Dan_P]

Hopefully he can Give us his thoughts soon, I’ve seen that test, seems a good technique.

what do you make out of this Dan?
I couldn’t find my ammonia test kit to verify if the previously idea was possible, instead I’ve been playing around with no3 test kit and it seems that my reagent can dissolve organics trapped in the sand bed.

if it wasn’t able to dissolve organics the sample with sand and RO should look like the test on the right that is RO only.
The water and the sand seem to have the same ppm concentration also. Any thoughts?

edit: my test kit work on fresh water also.

Cool! What was your procedure?

 

[sixty_reefer]

To the best of my knowledge Dan, it came from the commercial seahorse aquaculture industry overseas. When looking for reasons for seahorse mortalities and normal nutrient testing and whatever else they were doing in the lab didn't indicate a problem, someone picked on DO to lab test and over some period of time they determined that higher DO led to the problems but if DO was kept from increasing they didn't have problems. When DO levels increased it was noted that nasty bacteria levels also increased along with pathogens such as ciliates that also kill so many seahorses via gill infestation.
Unfortunately, hobbyists can't afford to pay for lab testing all the time.
I don't know if they did some kind of Dissolved Organics test or a Dissolve Organic Carbon test. It seemed to have been about a decade ago when this knowledge hit the hobby scene and since then the recommendation is to use a skimmer rated a minimum of 2X tank volume but larger is better. Also, it takes excellent filtration, tank husbandry and large water changes more frequently, cleaning anything that traps uneaten food and detritus BEFORE decomposition sets in and increased nutrient and DO levels in the tank.
So, if you still end up down the road with say a nasty bacterial infection, you then are advised to not just treat the seahorse in a hospital tank but revise your tank situation to be more extreme so less of a chance of increasing DO.

I believe you confusing things, your concern in your hobby is the same as reefing, that is the build up of organic matter in the water column that can cause the yellow tint on the water and nuisances. Dissolved organic carbon is actually a good thing as it will aid the growth of beneficial bacteria that assimilates phosphates and nitrates and is then removed from the system via skimming. Most sea horse systems just as reefs tent to be Dissolved carbon limited and often it needs to be manually added to a system the main issue that you have also is that sea horse can’t take much flow meaning that most proteins will tend to scatter around the bottom of the tank and don’t reach the protein skimmer section allowing it to deteriorate in the system and cause the issue that you mentioned. All you need is to know how to interpret in what nutrient the system may be limited as it’s not always limiting by dissolve organic carbon, many times phosphates and nitrates can also limit the heterotrophic bacteria from assimilate nutrients and cause several chain reactions in a system, I’ve wrote a fairly complicated thread that can indicate in what nutrients a system may be limited without having to do expensive testing, if you wish I can post a link here for it.

 

[sixty_reefer]

Cool! What was your procedure?

Standard procedure for this test kit, for the middle test I’ve removed some sand from my system and removed all water with paper towel, added the dry sand + 10ml RO + reagent 1 and agitating for 1 minute then added reagent 2 agitating for 30 seconds and wait 10 minutes for colour to develop. Done test twice to make sure there wasn’t a glitch. I did not quantify the sand although with less sand the test showed less ppm. I imagine that if I was to calculate the total nitrates in the water and the total nitrates in the sand

 

[rayjay]

Sixty, I'm not confused with what I'm looking for but am confused on your take on the matter. It is NOT the same as a reef tank. We don't want DO even though it may help beneficial bacteria because it mainly helps produce more nasty bacteria especially like the vibrio species and that leads to the infections and death of many thousands of seahorses each year just in America. While some seahorses manage to survive in reef tank conditions, most will end up dying.
Just to pick another point in your comment, When I started in 2002, low flow was then the recommendation. Today, and for many years now, most of us in the hobby have a MINIMUM of 10x system volume for flow and many of us long term keepers are at 20X and above.
The intent is to have sufficient flow to keep the uneaten food/detritus in the water column long enough for it to be captured by mechanical filtration. Then clean that trapped material twice a week before decay produces the DO and other nutrients.
It is a fact that you can have NO detectible levels, or next to it, of anything the test kits can check for, but seahorses still die. Commercial breeders have determined that elevating DO is the major culprit and I see no reason why the same won't apply to the hobbyist, especially now that we are having MUCH greater success in keeping conditions such that DO doesn't get elevated.
As for your testing, I'm just not capable of understanding the workings of such matters so I have to depend on others to help me out. i.e. Randy was an invaluable aid to me when he was at RC, even helping to determine the makeup of the homemade water I have been using for decades now.

 

[taricha]

I don't keep seahorse, but still find this interesting. Just out of curiosity is there a correlation between UV absorbance and Oxidation Reduction Potential (ORP)?

The correlation is so weak that it's almost useless. Because there's strong ORP correlations with other things that go in, like vitamins and preservatives in foods.
If using a strong oxidizer like Ozone, then ORP becomes a very good marker for how well the ozone is working. otherwise not really.

@taricha, would chorine (bleach) consumption have a shot at indicating high v low DOC for the hobby? There is a Hanna Checker already for chlorine and the hobby already handles bleach.

yes, kinda.
bleach consumption seems to be dominated by organic N compounds and ammonia. Straight organic carbons without N don't seem to get noticed by chlorine in any timely way.
that said, if bleach reaction with organic N is probably a half-decent proxy for the organic load that you'd wish to remove.

When [Dissolved Organics] levels increased it was noted that nasty bacteria levels also increased along with pathogens such as ciliates that also kill so many seahorses via gill infestation.

I think this info tells us that Dan's idea below is the way to go...

Another way to use bacteria to tells how much digestible stuff is around is oxygen demand. @taricha used this in some of his investigations along with total phosphorous and total nitrogen test kits. I don’t remember all the details so when his schedule permits, he can bring us up to date.

BOD is going to measure both the digestible organics in the water as they are consumed and it would also detect metabolism by microorganism load like bacteria or ciliates.

dissolved oxygen digital probes are nice if you want to play with a bunch of measurements (I love mine) , but hanna sells a dissolved oxygen chemical test that would meet the needs of measuring BOD.

BOD is a literal measure of how much metabolism of oxygen is occurring in stored water. This tells you how much yummy organic junk is in the water and how digestible it is. This is actually more important than the much harder to measure total organic carbon, organic N & P tests.
Because undigestible organics are irrelevant to bacteria / ciliates etc.

If people's water is dirty, then a BOD1 (stored 1 day) test would be enough to give a good measure for comparison. If the water is pristine reef, it'd need to be BOD5 (5 days) to see much O2 consumption.

(more later on ways to remediate high BOD.)

 

[rayjay]

If people's water is dirty, then a BOD1 (stored 1 day) test would be enough to give a good measure for comparison. If the water is pristine reef, it'd need to be BOD5 (5 days) to see much O2 consumption.

I had to look up what BOD was but now I don't understand this BOD1 and BOD5. Does storing it make the levels higher?

 

[taricha]

I had to look up what BOD was but now I don't understand this BOD1 and BOD5. Does storing it make the levels higher?

Seawater has a max O2 level of ~7 ppm or so depending on temp.
If you store it sealed completely, then the O2 level will drop as it's used by organisms. BOD5 means stored for 5 days. Pristine low organic reef tank water will drop like ~1ppm or less in 5 days.
Water with more organics will drop O2 more and faster. Depending on how high the organic level is in the seahorse tanks, it may give easily measurable drops of O2 in much less than 5 days. Maybe only 1 or 2 days. That's what I meant by BOD1.

 

[Randy Holmes-Farley]

Thank you for your reply.
The problem we have with the hobby is that so many people just don't understand why they are losing their seahorses when all their test kits show the water to be great. It's hard to understand that something other than what all those test kits are testing for is making their water quality bad for seahorses. I was probably a decade into the hobby before I realized it.
Greatly oversized skimmers are probably the first recommendations we advise on in the last decade now, and if you can't have that then use the GAC. With no test kit we can use like other test kits, it's still a problem as the DO can build up very slowly even over a year's time give or take before it becomes problematic, or it can happen within months. It all depends on things like stocking density, feeding protocols, husbandry, filtration equipment and frequency and volume of water changes.
As all systems are different so there is really no way for us to advise newcomers as to their likely success with their specific tank with what they have and do. If we had a test kit then they could see for themselves if their setup and protocols are sufficient.
While the Triton test does give a measure, it's too expensive to use as often as we would need it in the hobby, at least for most hobbyists.
I think I'm looking for the Holy Grail.

It’s a seemingly valid hypothesis that increased organics lead to more bacteria that may lead to more infections, but I would not assume it is correct.

infections in other organisms do not happen just because there is organic matter present.