Reasons for Doing Water Changes?

[CNDReef]

It’s a beautiful tank, how long has it been running?

 

[Lasse]

According to my experiences - it looks like low molecule weight and short chain DOC ´s are the limited factor for the growth of heterotroph bacteria in a reef aquaria. That’s the reason why the Vodka trick works so well. To measure this type of DOC´s you can chose the BOD5 or BOD7 method. High weight and long chain DOC molecules like yellowing substances is not easily brook down by bacteria. This type of DOC – you can measure with help of the COD method. (BOD5 and BOD7 stands for Biological Oxygen Demand – 5 days and Biological Oxygen Demand – 7 days. COD stands for Chemical Oxygen Demand)

Sincerely Lasse

 

[SPR1968]

I’ve been following along with this and many other threads regarding water changes and wether they are necessary.

I personally due around a 20% water change in my Max S 650 every 7-14 days and having set my first ‘largish’ reef tank up in June 2016 this has served me very well. I’ve always done 10% weekly, but since the tanks been running around 16 months I have started doing bigger changes, mainly because I’ve made it a lot easier using high powered pumps and long hoses to do all the work for me. The days of carrying water buckets it over! It literally takes me a few minutes to set up the hoses and then take out 110litres with a Python from my sump, and then pump back in fresh saltwater with a pond pump.

I also auto dose or manual dose the various additives that are required for stable water parameters in addition to water changes, virtually entirely using the Red Sea Reef Care Program.

I don’t have a problem with people who don’t want to change water, but from what I’ve read most of those are fairly experienced and advanced aquarists with a lot of experience behind them, and can recognise problems hopefully before they cause issues. Your average reefer may not.

I think the problem is that you average reefer would just run into major problems doing no changes with all the contaminates building up, and therefore I can see were it’s sort of become standard practice and ‘best advice’ to do weekly water changes, to avoid these problems for most people.

I can see that with modern equipment, protein skimmers etc, and I use most of it myself, that the water quality can be kept very good, but do you know what, it just makes me feel better that I’m providing the inhabitants of my tank with the best home, and best quality environment I possibly can and in my mind putting fresh saltwater in must be good.

Anyway just my thoughts......

 

[gregkn73]

According to my experiences - it looks like low molecule weight and short chain DOC ´s are the limited factor for the growth of heterotroph bacteria in a reef aquaria. That’s the reason why the Vodka trick works so well. To measure this type of DOC´s you can chose the BOD5 or BOD7 method. High weight and long chain DOC molecules like yellowing substances is not easily brook down by bacteria. This type of DOC – you can measure with help of the COD method. (BOD5 and BOD7 stands for Biological Oxygen Demand – 5 days and Biological Oxygen Demand – 7 days. COD stands for Chemical Oxygen Demand)

Sincerely Lasse

It is the first time I read that we can measure the different Doc's with any method! Very interesting. Can you give us a link , or more info about those methods?

 

[dz6t]

My point was - I am considering a test - that likely will be 'normal' and will cost me money.
If it is abnormal - (a sky high xxx level - an extremely low yyy level) - there will be no data as to what it means, where its from or whether its significant.
FWIW - all instruments have 'margins of error'. and Im not aware how triton choses their 'normal range'.
Also - check out a couple threads where they sent 3 tests to 3 places and got 3 fairly different results.

Like I said - even given the above 'concerns' - I will probably buy a test - PT Barnum.

ICP-OES can give false high or low numbers.
High numbers can be caused by interference from other elements. I am a chemist and I am well aware of this instrument’s limits.

If someone is doing ICP-MS, the results are more reliable. But if you bring a saltwater sample to a lab and request ICP-MS, and if I was running the lab, I would show you the door. Lol

That is why calibration is critical.

 

[Randy Holmes-Farley]

ICP-OES can give high or low numbers.
High numbers can be caused by interference from other elements. I am a chemist and I am well aware of this instrument’s limits.

If someone is doing ICP-MS, the results are more reliable. But if you bring a saltwater sample to a lab and request ICP-MS, and if I was running the lab, I would show you the door.

That is why calibration is critical.

ICP-MS has interferences too, and while the detection limits can sometimes be lower, the interferences are totally different and it can be worse, in some cases, than ICP-AES.

I reviewed one salt mix study years ago that used ICP-MS, and I had to point out that some of the results were incorrect due to interferences.

 

[Newb73]

They are always present. I'm not sure there's anything you can do to promote their growth that you would not be already doing for a reef tank, except possibly providing more surface area for them to grow.

I suspect a problem with the cutesy sparsly aquascapped tanks in the name of "eliminating dead spots".
I experimented with that way to and the tank was always struggling.

I filled it close to half full with rocks, put a bunch of exrta substrate in the fuge and dead spots be darned, the tank is way healthier with the increased substrate and surface space.

Old school wins.

 

[dz6t]

ICP-MS has interferences too, and while the detection limits can sometimes be lower, the interferences are totally different and it can be worse, in some cases, than ICP-AES.

I reviewed one salt mix study years ago that used ICP-MS, and I had to point out that some of the results were incorrect due to interferences.

Agree.
At least the MS has a lower detection limits and hopefully get more accurate numbers for trace elements instead of zero readings by OES.

 

[Lasse]

It is the first time I read that we can measure the different Doc's with any method! Very interesting. Can you give us a link , or more info about those methods?

None of the methods measures the exact amount of dissolved organic carbon – instead they give a relative value in terms of how much oxygen is required to oxidize the organic content in the water. BOD 5 (or BOD 7 in Sweden) provides a value for the dissolved organic carbon that is oxidized by bacteria for 5 or 7 days. In order to get the dissolved part you must filter the sample before you start the test. Link

The COD test measure how oxygen that is needed in order to totally oxidize the organic matter in the water. Link

Both methods could be used in aquaria (theoretical) but practical – no. Its too expensive and need lab equipment’s.

Personally I use another indirect method in order to see if I have a lot of persistent DOC in the system. (the part of the DOC that is biodegradable (BOD5 or BOD7) does not concern me)

A part of the persistent DOC is what we call yellowing substances – or CDOM (Colouring Dissolved Organic Matter). What I`m doing is that I take up 10 – 15 litre of aquarium water and put it in a white bucket. Now - its easy - even with my old eyes - to see if there is any yellow tint in the water. If you are doing a WC – compare with the same amount fresh mixed water in similar bucket. This CDOM is one of the toughest DOC to oxidize so it’s a good indicator that you are free of dangerous amounts of toxic DOC if the water lack the yellowing tint. However - If you do have a yellow tint (you will have it if you only use WC as a method) – its no panic CDOM is normally not toxic in any way. How to take away the CDOM? Active Carbon is one way but another method is to oxidize them in a chemical way. Ozone is well-known (and you do not need much of it) – another way is to use an oxidator – an equipment that works without electricity and dose small amounts of hydrogen peroxide to the aquarium and can´t poison your air there you live

I hope you get the answers you want

Sincerely Lasse

 

[Lasse]

I’ve been following along with this and many other threads regarding water changes and wether they are necessary.

I personally due around a 20% water change in my Max S 650 every 7-14 days and having set my first ‘largish’ reef tank up in June 2016 this has served me very well. I’ve always done 10% weekly, but since the tanks been running around 16 months I have started doing bigger changes, mainly because I’ve made it a lot easier using high powered pumps and long hoses to do all the work for me. The days of carrying water buckets it over! It literally takes me a few minutes to set up the hoses and then take out 110litres with a Python from my sump, and then pump back in fresh saltwater with a pond pump.

I also auto dose or manual dose the various additives that are required for stable water parameters in addition to water changes, virtually entirely using the Red Sea Reef Care Program.

I don’t have a problem with people who don’t want to change water, but from what I’ve read most of those are fairly experienced and advanced aquarists with a lot of experience behind them, and can recognise problems hopefully before they cause issues. Your average reefer may not.

I think the problem is that you average reefer would just run into major problems doing no changes with all the contaminates building up, and therefore I can see were it’s sort of become standard practice and ‘best advice’ to do weekly water changes, to avoid these problems for most people.

I can see that with modern equipment, protein skimmers etc, and I use most of it myself, that the water quality can be kept very good, but do you know what, it just makes me feel better that I’m providing the inhabitants of my tank with the best home, and best quality environment I possibly can and in my mind putting fresh saltwater in must be good.

Anyway just my thoughts......

What I´m trying to say is that the assumption that the WC always will give you a perfect water and with no risk to add some contaminants to your aquarium can be wrong. The risk that you add something dangerous can be as high as the assumption that you take away something dangerous. IMO - It’s a false safety if you do not buy a very, very expensive salt that’s done in small batches.



The ICP test – type the one from Triton – is the only test that today can give a little better understanding of what’s happen in the aquaria – its not perfect but it’s a tool



Sincerely Lasse

 

[MnFish1]

Here's a video of Ricos Reef from Tidal Gardens

Acros, sps, LPS, heaps of fish; amazing tank.
Filtration is a macroalgae fuge & a very large skimmer. No activated carbon or GFO.
Calcium reactor, and suppliments extra trace elements through feeding. Thats it.
Zero water changes

Quote from the video: "Rico does several things differently than I would do or that I would recommend other people to do". "For example he does no water changes"

Ok - so - He has a 300 gallon tank - and at least 300 gallons of filtration - between the frag tanks, 150 gallon sump and his chateo reservior. I guess I tried to make the point before that its easier to do no water changes with a system like this. Its funny - read through these forums - there are enough people that mention problem after problem with smaller tanks when they forget to do water changes. People with rising Nitrate, and algae problems, etc. There are a lot of reasons for this - they dont have the money for a sump and filtration system as large as their tank, the room, etc.

 

[Newb73]

None of the methods measures the exact amount of dissolved organic carbon – instead they give a relative value in terms of how much oxygen is required to oxidize the organic content in the water. BOD 5 (or BOD 7 in Sweden) provides a value for the dissolved organic carbon that is oxidized by bacteria for 5 or 7 days. In order to get the dissolved part you must filter the sample before you start the test. Link

The COD test measure how oxygen that is needed in order to totally oxidize the organic matter in the water. Link

Both methods could be used in aquaria (theoretical) but practical – no. Its too expensive and need lab equipment’s.

Personally I use another indirect method in order to see if I have a lot of persistent DOC in the system. (the part of the DOC that is biodegradable (BOD5 or BOD7) does not concern me)

A part of the persistent DOC is what we call yellowing substances – or CDOM (Colouring Dissolved Organic Matter). What I`m doing is that I take up 10 – 15 litre of aquarium water and put it in a white bucket. Now - its easy - even with my old eyes - to see if there is any yellow tint in the water. If you are doing a WC – compare with the same amount fresh mixed water in similar bucket. This CDOM is one of the toughest DOC to oxidize so it’s a good indicator that you are free of dangerous amounts of toxic DOC if the water lack the yellowing tint. However - If you do have a yellow tint (you will have it if you only use WC as a method) – its no panic CDOM is normally not toxic in any way. How to take away the CDOM? Active Carbon is one way but another method is to oxidize them in a chemical way. Ozone is well-known (and you do not need much of it) – another way is to use an oxidator – an equipment that works without electricity and dose small amounts of hydrogen peroxide to the aquarium and can´t poison your air there you live

I hope you get the answers you want

Sincerely Lasse

What I´m trying to say is that the assumption that the WC always will give you a perfect water and with no risk to add some contaminants to your aquarium can be wrong. The risk that you add something dangerous can be as high as the assumption that you take away something dangerous. IMO - It’s a false safety if you do not buy a very, very expensive salt that’s done in small batches.



The ICP test – type the one from Triton – is the only test that today can give a little better understanding of what’s happen in the aquaria – its not perfect but it’s a tool



Sincerely Lasse

Unless you are in a small space, run a much larger generator than is needed, run without a controller, do not run your exit from a reactor through carbon, and are just plain incompetent, reports of Ozone toxicity are grossly exaggerated.

 

[Randy Holmes-Farley]

Unless you are in a small space, run a much larger generator than is needed, run without a controller, do not run your exit from a reactor through carbon, and are just plain incompetent, reports of Ozone toxicity are grossly exaggerated.

Most reefers actually do not seem to run the air effluent through GAC.

 

[TbyZ]

From another forum, 10/10/2017

I have a 150 reef tank running well for 8 years and i've been regularly using io rc salt. and this week the unthinkable happened. did a water change recently with io rc. then had to be away from home for a week for a business trip. a couple days later i saw some of my sps started bleaching. after investigating, something wasn't right with the water. tested my params and found my mg and ca dropped drastically. everything read normal except my mg was down to about 800 and ca 120
so i frantically mixed a new bucket of salt water with the io rc and to my horror, there were hardly any traces of ca or mg. salinity read 1.026 and dkh and ph read normal. the salt bags looked normal. no clumping. i buy 200 gall boxes from amazon. nothing out of the ordinary. i wasnt ready to accept the fact that this was a bad batch of salt. so my buddy gave me a bag of his regular io salt tonight and i just tested a newly mixed batch of water using io salt. to my dismay, the io mixed normal. mg in the 1400s and ca in the 400s. so that proves that none of my test kits were off. it was the salt! ugghhh

i dont have ro water handy so i am making some right now, but my sps corals are literally dying by the hour. it is painful to watch. fish seem ok, and lps look all bloated.

i admit i never test my new water. just for salinity and ph. i had no idea that there could be batches with no ca or mg. this was a painful lesson learned.

 

[ksed]

"Dr. Haas, et al, found the only times DOC dropped to zero around reefs was in highly eutrophic systems completely taken over by algae and heterotrophic bacteria".

I hadn't considered the usefulness of algae beyond nitrogen & phosphate removal. Obviously very efficent at removing apparently all DOCs.

Must be why Triton utilise a macro refugium.

I just read somewhere that algae releases 7X more DOC than corals. I try to see if I can find the article.

 

[TbyZ]

I just read somewhere that algae releases 7X more DOC than corals. I try to see if I can find the article.

Where does the DOC that corals release come from? Photosynthesising zooxanthellae

 

[TbyZ]

From another forum, 10/10/2017

I have a 150 reef tank running well for 8 years and i've been regularly using io rc salt. and this week the unthinkable happened. did a water change recently with io rc. then had to be away from home for a week for a business trip. a couple days later i saw some of my sps started bleaching. after investigating, something wasn't right with the water. tested my params and found my mg and ca dropped drastically. everything read normal except my mg was down to about 800 and ca 120
so i frantically mixed a new bucket of salt water with the io rc and to my horror, there were hardly any traces of ca or mg. salinity read 1.026 and dkh and ph read normal. the salt bags looked normal. no clumping. i buy 200 gall boxes from amazon. nothing out of the ordinary. i wasnt ready to accept the fact that this was a bad batch of salt. so my buddy gave me a bag of his regular io salt tonight and i just tested a newly mixed batch of water using io salt. to my dismay, the io mixed normal. mg in the 1400s and ca in the 400s. so that proves that none of my test kits were off. it was the salt! ugghhh

i dont have ro water handy so i am making some right now, but my sps corals are literally dying by the hour. it is painful to watch. fish seem ok, and lps look all bloated.

i admit i never test my new water. just for salinity and ph. i had no idea that there could be batches with no ca or mg. this was a painful lesson learned.

Another from this forum -

I have ran R/C for my salt for years, but I had recently noticed that I seem to be getting a film on my circulation pump and the bigger problem is that the last box I received had low magnesium, with 0 tds RODI water at a .026 salinity I tested it at 800. So I thought this was a bad batch so I replaced it what the heck a new box and it tested out at 850. Sothat being the case I switch...

Worse than Lasse suggested

 

[ksed]

None of the methods measures the exact amount of dissolved organic carbon – instead they give a relative value in terms of how much oxygen is required to oxidize the organic content in the water. BOD 5 (or BOD 7 in Sweden) provides a value for the dissolved organic carbon that is oxidized by bacteria for 5 or 7 days. In order to get the dissolved part you must filter the sample before you start the test. Link

The COD test measure how oxygen that is needed in order to totally oxidize the organic matter in the water. Link

Both methods could be used in aquaria (theoretical) but practical – no. Its too expensive and need lab equipment’s.

Personally I use another indirect method in order to see if I have a lot of persistent DOC in the system. (the part of the DOC that is biodegradable (BOD5 or BOD7) does not concern me)

A part of the persistent DOC is what we call yellowing substances – or CDOM (Colouring Dissolved Organic Matter). What I`m doing is that I take up 10 – 15 litre of aquarium water and put it in a white bucket. Now - its easy - even with my old eyes - to see if there is any yellow tint in the water. If you are doing a WC – compare with the same amount fresh mixed water in similar bucket. This CDOM is one of the toughest DOC to oxidize so it’s a good indicator that you are free of dangerous amounts of toxic DOC if the water lack the yellowing tint. However - If you do have a yellow tint (you will have it if you only use WC as a method) – its no panic CDOM is normally not toxic in any way. How to take away the CDOM? Active Carbon is one way but another method is to oxidize them in a chemical way. Ozone is well-known (and you do not need much of it) – another way is to use an oxidator – an equipment that works without electricity and dose small amounts of hydrogen peroxide to the aquarium and can´t poison your air there you live

I hope you get the answers you want

Sincerely Lasse

How much HP do you use per gallon of water volume.
Also HP have stabilizers, which can present itself with concerns as well.

 

[ksed]

Where does the DOC that corals release come from? Photosynthesising zooxanthellae

Slime

 

[TbyZ]

Slime

Mucus.
The zooxanthellae transport the DOC they produce to the coral. The coral excretes the DOC in its mucus. Bacteria eat the DOC in the coral mucus & multiply. The coral eats the bacteria.