This debate will last through eternity! But it's 2020 and have things changed?

[Doctorgori]

On the topic of water changes
@MnFish1 got my doggone head spinning <LOL> I’m trying to wrap my head around this as I’m really trying to escape as many H2O changes as possible,,,,, I’m no math major
a story problem: Say you need to dilute your tank by 80% to get a “pollutant” to within tolerance
Isn’t doing 2ea 40% changes LESS dilutive than one 80% change?
I’m not arguing just embarrased to try the math and/or I’m missing the blatantly obvious

 

[Clownfish_Boy]

To the second quoted post I think you need to relook at science as our reef tanks are nothing but a science experiment that either succeed or do not and to say they are anti science is completely wrong

If reefing ain't science, then I don't know what is ! All the testing and monitoring we do on our setups, ad infinitum....

 

[Lasse]

They simply do continual water changes with natural seawater. In other words, when the experts with effectively unlimited resources for growing corals are given the option... they choose to do more water changes than we do, rather than less.

That's are a total different scenario - all of what you need are there in unlimited amount. That´s not the same as to mix artificial saltwater with RO water and dry mixed salt as I state before.

Sincerely Lasse

 

[MnFish1]

yes, I get it ....appreciate the post ... I’m talking this through, while were are at it, I’m not debating just maybe the goals might be tangent.
I have to disclaimer this as its just on memory, from older assorted threads on the subject and a articles I read on water changes a long time ago, I don’t have the exact references.
For dilution, isn’t it a regression problem in math? or so I thought anyway. The thinking as I remember it was this (grossly paraphrasing) . In that removing 1% of a solution 10 times x isn’t as dilutive as 10% at once, thats as I recall it anyway.
Edit add: yes I love that one: water change calculator and this: Reef Chemistry

I'm not sure - thats why I just used the calculator lol.... The calculator suggests - that if regularly done - doing small changes more often - is quicker - than doing larger changes less often - but - those curves will cross, right? Lets assume your nitrate is 50 - and you change 100 percent of your water - now your theoretical nitrate is 0 - in one day. It would take a year of smaller changes to make the same change. I was just using your data that you posted - about your regimen. There is no right or wrong - basically

 

[MnFish1]

On the topic of water changes
@MnFish1 got my doggone head spinning <LOL> I’m trying to wrap my head around this as I’m really trying to escape as many H2O changes as possible,,,,, I’m no math major
a story problem: Say you need to dilute your tank by 80% to get a “pollutant” to within tolerance
Isn’t doing 2ea 40% changes LESS dilutive than one 80% change?
I’m not arguing just embarrased to try the math and/or I’m missing the blatantly obvious

Note - there is also a bit of a difference that that calculator does not take into account - the end result is 'amount of new water' vs 'old water' at a certain period of time. What I dont know Is - (and this is important) - the day after 'new water' is added - to me it becomes 'old water'. Right? I am hoping @Randy Holmes-Farley will weigh in - because my guess is this is going to involve calculus - and other equations - that I dont remember

 

[MnFish1]

That's are a total different scenario - all of what you need are there in unlimited amount. That´s not the same as to mix artificial saltwater with RO water and dry mixed salt as I state before.

Sincerely Lasse

@Lasse Hallå - here is a question - so would you say - then that a system that changes x percent of water with freshly mixed salt water would be equivalent? (Btw - I dont know how much water is changed in the aquarium - I thought you might know) - if its 100 percent per day - its a no brainer..

 

[SaracensRugby]

I have said it before and I will say it again. According to trace elements - WC is not a safe tool. There is no way that any can guarantee that the trace metal content is the one described in every bag of dry salt manufactured. How do you evenly mix in 1 g in 1 metric ton and have the same concentration over the whole batch (if it is just 1 metric ton) ? I´m not against WC if you aim to correct something that´s wrong - but I will not use WC as a scheduled tool. This is if you use RO water for top of. If you use tap water for top off - when some WC maybe should be done.

Sincerely Lasse

Hey @Lasse, what about salts that are batch tested? I buy Salinity salt, and it has the measurements of elements in each bucket. I never look to go that deep into each one, but know when I have gotten my Triton tests everything comes out fine. So I pay more for salt to think less.

Or at least that is my thought anyway.

 

[zachtos]

Sounds about right LOL!

This hobby has historically suffocated under anecdotes and rules-of-thumb. Making forceful claims based on opinion is still just opinion. My approach to these things is that 'your' opinion doesn't matter and my opinion doesn't mater. They're either important or they're not. Since there is really no data one way or the other, I'll keep doing them just to be on the safe side. Imagine that's why places like WWC keep doing them.

I agree a ton of information in this hobby is anecdotal. BUT, now we have concrete lab test that tell you exactly what is going on in your tank. $50ish per test, but well worth it for large expensive systems. I know for a fact I could never keep some of my minerals up with water changes, supplementation is mandatory, or the corals will starve for some elements.

 

[zachtos]

Then lets start with indisputable facts.

(1) Salt mixes do not contain any industry standard of trace elements.

(2 The reefing industry doesn't even agree on what a trace element is.

(3) One salt mix may consider potassium to be a trace element, then put 'contains trace elements' on the label. Reefers then assume it's uranium or unobtanium then start threads about how often they should do water changes because they contain trace elements.

(4) Replace the term 'Trace Elements' with 'Britney Spears' when you see somebody seriously talking about Trace Elements. It's fun, and often makes more sense,

(5) There are a lot of amazing SPS tanks posted on this very site where the owner does very infrequent or no water changes at all. Therefore you cannot logically conclude water changes are a requirement, or make up psuedo science that claims they are required.

Tanks with minimal or no water changes should be our goal, not putting your thumbs in your ears and go 'la la la I can't hear you' because of purchase justification.

yes, I have been 2 years no WC w/ my 300G SPS and doing better than I have with my last several tanks. I do less labor, spend less money, and get better results. It's all because ICP test is now available and affordable.

I agree no one knows the answer on required minerals, so we just try to replicate the numbers in the ocean. I have deviated a bit on several elements with no negative consequence yet (molybdate, boron, silica).

 

[Doctorgori]

I'm not sure - thats why I just used the calculator lol.... The calculator suggests - that if regularly done - doing small changes more often - is quicker - than doing larger changes less often - but - those curves will cross, right? Lets assume your nitrate is 50 - and you change 100 percent of your water - now your theoretical nitrate is 0 - in one day. It would take a year of smaller changes to make the same change. I was just using your data that you posted - about your regimen. There is no right or wrong - basically

Note - there is also a bit of a difference that that calculator does not take into account - the end result is 'amount of new water' vs 'old water' at a certain period of time. What I dont know Is - (and this is important) - the day after 'new water' is added - to me it becomes 'old water'. Right? I am hoping @Randy Holmes-Farley will weigh in - because my guess is this is going to involve calculus - and other equations - that I dont remember

Man I’m not 100% sure either anymore now thanks to you <LOL>
thats why I’m fishing not arguing.... I’m still thinking its two mathematically diametric but supportive goals: replenishment vs.dilution ....
In my mind smaller is better when it comes to element replacement but maybe 1 big change is better from a dilutive POV...
No way 7 10% changes dilutes as much as 1 70% .... thats like thinking 3 50% changes is better than a 100% change ... in scenarios one thats 50 of 50 of 50 so by day 3 you still are only the 87%, or will my math embarrass me?
I dunno, math anyone?

 

[MnFish1]

I agree a ton of information in this hobby is anecdotal. BUT, now we have concrete lab test that tell you exactly what is going on in your tank. $50ish per test, but well worth it for large expensive systems. I know for a fact I could never keep some of my minerals up with water changes, supplementation is mandatory, or the corals will starve for some elements.

Disagree - I have never ordered a test - and a test costs the same as a bucket of salt......

 

[zachtos]

do ice tests measure dissolved organics?

No, but I do have nutrient exportation as well. Carbon, Skimmer, algal turf scrubber and live rock all help fill in the blanks for a closed loop. So other than adding minerals in, you can visually identify if there is a problem in the tank as well (canary in coal mine corals).

 

[MnFish1]

Man I’m not 100% sure either, thats why I’m fishing not arguing.... I’m still thinking its two mathematically diametric but supportive goals: replenishment vs.dilution ....
In my mind smaller is better when it comes to element replacement but maybe 1 big change is better from a dilutive POV... I dunno, math anyone?

@Randy Holmes-Farley

 

[MnFish1]

No, but I do have nutrient exportation as well. Carbon, Skimmer, algal turf scrubber and live rock all help fill in the blanks for a closed loop. So other than adding minerals in, you can visually identify if there is a problem in the tank as well (canary in coal mine corals).

Just to play devils advocate - (I think I deserve a special badge @revhtree ) - You cant know - what those things are. You cant measure them well (at least most people don't) - and don't need to - because they do water changes.. Or>?

 

[zachtos]

Disagree - I have never ordered a test - and a test costs the same as a bucket of salt......

for me, cost more. Probably based on tank size and how frequent you sample (I do every 2-3 months). di resin, water (City), salt, and replacing minerals is still required.

 

[zachtos]

Just to play devils advocate - (I think I deserve a special badge @revhtree ) - You cant know - what those things are. You cant measure them well (at least most people don't) - and don't need to - because they do water changes.. Or>?

very true. but a TON of the MYSTERY of reefkeeping has been removed with the advent of ICP testing. 15 years ago my old reef I had no clue what was going on. I am now sure that I was always deficient in MANY of my minerals, as certain corals seem to suck down different minerals. I can barely keep up with weekly specific trace dosing, so a 10-20% WC will not even come close to bumping those levels up, they'd be back to zero in a day for me. Probably just like my old tank.

 

[zachtos]

I tried to do the “Look ma, no water changes” thing ...it failed
I haven’t given up on my quest however ... I spend $40/mo on salt
I haven’t given up .... trying Balling Hybrid with Kalk+2 ...we’ll see how long that last...
When is someone going to give us RELIABLE inexpensive & easy trace element testing?
Edit add: 2-3% daily H2O changes makes absolutely no mathematical sense...
if you are worried about stability 7-10% every 3-7 days is waaaaay better and is a better compromise IMO

I have had fantastic success for 2 years now on my 300G SPS. You have to do ICP test every 2-3 month ($50). Doing water changes is actually bad for this system, because I know the average consumption of 10-20 different minerals, so water change would break my calculations. I DIY all the chemicals though, so not sure if it's cheaper if buying store made mangenese, boron, vanadium etc

 

[Doctorgori]

yes, I have been 2 years no WC w/ my 300G SPS and doing better than I have with my last several tanks. I do less labor, spend less money, and get better results. It's all because ICP test is now available and affordable.

I agree no one knows the answer on required minerals, so we just try to replicate the numbers in the ocean. I have deviated a bit on several elements with no negative consequence yet (molybdate, boron, silica).

300 gallons is the thing here, that 29 bucks for a ICP is worth it at 60 gal of salt/mo At some point For smaller tanks just solving for a real or imaginary problem is cheaper in salt.
In fairness however I must admit my failure at no water change was pre ICP, pre Salinity drift knowledge

 

[adobo]

I agree a ton of information in this hobby is anecdotal. BUT, now we have concrete lab test that tell you exactly what is going on in your tank. $50ish per test, but well worth it for large expensive systems. I know for a fact I could never keep some of my minerals up with water changes, supplementation is mandatory, or the corals will starve for some elements.

I assume you are referring to ICP testing.

In general, this is a great development for the hobby. There are some though that question the validity of ICP testing. Jack Kent from Brightwell is one who seems to be very vocal about the quality of the data you will get from those who offer ICP testing.

 

[zachtos]

300 gallons is the thing here, that 29 bucks for a ICP is worth it at 60 gal of salt/mo At some point For smaller tanks just solving for a real or imaginary problem is cheaper in salt.
In fairness however I must admit my failure at no water change was pre ICP, pre Salinity drift knowledge

100% this. You can't do no WC with high success without knowing the levels in the system. And yes, I would not recommend that system to anyone under 240G unless they want to spend more money. A yearly test wouldn't be a bad idea though in any system, to bump up those critically low elements.