Water changes... out loud thoughts

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Reefer James

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So I wanted to break down water changes down to how I see them. Basically we have to consider there are 3 reasons to ultimately do a water change.
1) Removing fish waste
2) Resupplying coral with trace elements and everything else in salt mix
3) Nutrients control

So now let’s consider how we approach a water change. If all we are doing is sticking a tube into the water draining water out and simply putting new water in this is going to do #2 and #3 but not remove noticeable fish waste. So why not just really shake up the sand and then suck it all up. This will actually release more nutrients into the water than you would have been taking out, and potentially releasing more fish waste into the water. Don't do it.

Lets assume the main reason we’re doing water changes is because we do not want to dose elements and know by doing a water change we are taking out water with low ppm and adding in higher ppm of certain elements water. Removing 380ppm calcium, and adding 500ppm salt mix into the tank can restore levels on a smaller system. I’d have to say a water change of at least 50% would be necessary (with a good amount of hard coral) to get enough ca, mg, and kh ultimately. I mean it will do wonders towards keeping ionic balance and providing those minor & trace elements. In a 60g tank a 50% weekly water change is going to cost around $120 a month! DANG! Liquid dosing isn’t even that much and dry powder is even cheaper.

If all you’re keeping is soft corals your levels may not decrease as quickly but surely they will. And if you have a lot of soft corals it could go quicker. Relying on a water change for elements required for corals to grow can put your live stock at risk. If you forget, or get busy these levels will continue to drop. If we get so busy we cannot do water changes the corals life could become at risk.

It is also possible to assume if our only purpose for WC is elements, if we’re in a rush but want to keep animal going, we may just drain water and not remove fish waste…

Let’s consider water change for the purpose of nutrients being too high. Phosphate is a level aquarist try and keep in trace levels. If you’re at .05 phosphate and want to go down to .03 it’d take almost a 50% water change.. I would also like to ask everyone if we’re okay with keeping nitrate at 10,000 times NSW why do we worry about phosphate being elevated? There are many examples of aquarist whom have 0.01 phoshate but suffer from hair algae? How can this be so? There’s a few things that dictates algae.. I will not get into it.

If you’re doing water changes to lower nutrients I’d encourage you to step back and wonder why are my nutrients raising and how can I prevent this. Are my circulation pumps moving sand around? Do I have a wrasse who’s digging too much? Have I not removed fish waste in a while?

The single most important thing that a water change [should] achieves is removing built up waste. Detritus and other waste can have serious impacts on corals, including death. High nutrients may effect color pigmentation and growth rates but it will not kill the coral.. there is also a difference between nutrients in the water column and nutrient waste.

It is my opinion that if we are going to do a water change our absolutely main priority needs to be removing the waste from the substrate, filter, and rock. And very slowly as not to release it back into the water column.

Dosing options for ca/kh/mg are much more efficient, and cost effective than relying on water changes. It is very true for some aquariums a water change makes more sense than dosing because the small amount of corals and coralline algae does not dictate frequent dosing. Cheers, you have designed a low maint coral reef! Keep up the good work.

For the rest of us who have corals who use up calcium like the growing hard skeleton animals they are, we should consider a balanced 2-part system.

The biggest thing for me is ratio. Keeping balance in tact is very important to the reef, in my opinion. If you’re just doing calcium chloride, bicarbonates, and magnesium chloride, you’re completelying leaving out items such as strontium, boron, and many more elements.

A good 2-part or even individual calcium product will contain elements other than calcium in a balanced ratio. Without this balance we will rely on water changes to keep the ratio. (Even nitrogen and phosphate are found in a specific ratio and naturally removed in the same ratio. When we use media like GFO we disrupt this ratio. Refugium or bio-pellets will preserve the balanced ratio. We can talk about this if anyone is interested. Obviously GFO is great at what it does, but have we considered the ratio of removal?)

Daily dosed 2-parts will even supply trace elements to the water.

Even with a great 2-part system the salt-mix has everything you need in the ideal ratio and balance. A water change is 99% of the time a good idea for corals…

A lot of aquarist wonder “How often should I be doing a water change and how much water”

Much of this answer relys on which of the 3 reasons you’re doing a water change. If you’re on the Red Sea program testing everything and then resupplying everything then your main purpose of water change is just to remove fish waste. With higher flow most of this fish waste is actually already found in the sump/filter. If you have smaller community fish it is likely you do not need to do water changes often, especially if you skim well and have a larger system.

The smaller the system the more need for water changes always. Levels increase AND DECREASE quicker in smaller volume of water. The smaller the skimmer the more water changes too… To put a number on it is ridiclious but I would say more.

If you’re hardly dosing, and have decent amount of hard corals you should be doing more like weekly water changes if not more frequent.

If you have a grouper and stingray you’re feeding a pack of silversides a day to, may need to do heavier more frequent water changes.

If you have a 55g FOWLR, you feed 3x a week and only 4 fish (lets say 3 nemo and a dori) you really don’t need to water change often… Especially considering nitrate is not that toxic. But no animal can live in it’s own poo for ever…

Anyway I feel like I have rambled a little and will see if there are any responses to expand this topic on.
 
I don't know much here.. have read that disturbing the sand bed is a nono??

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I don't know much here.. have read that disturbing the sand bed is a nono??

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Thanks for the contribution. As I touched on, it would negatively release more nutrients into the water. I also encouraged slow waste removal as to prevent any being released back into the water :)

It is a big nono haha
 
Thanks for the contribution. As I touched on, it would negatively release more nutrients into the water. I also encouraged slow waste removal as to prevent any being released back into the water :)

It is a big nono haha

My b, so many words such a deficit of attention;)

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Depends who you ask on if disturbing the sandbed is a good or a bad idea. I don't do it. Melev on the other hand thinks it is a good idea and I will link an article he did about it under this. I'm not really sure what Randy Holmes-Farley thinks.
EDIT: Removed the link, it wasn't for washing the sandbed but for transfering one from one tank into another...which I never advocate personally. I'll have to find the reference later.

Now, when it comes to water changes these are simply minor maintenance. The recommended 10% is to keep chipping away at a problem you can never get away from. That is why when we are using it as a nutrient export after a problem already exists, we say large and frequent water changes to get those down to 0.

When it comes to maintaining the elements, the same rule applies really. It takes one heavily stocked SPS tank to have a major drain on them. That is the reason I only say dosing is necessary for the most heavily stocked tanks.

When it comes to those smaller tanks, you are right about those water changes. That is even why I say skip a skimmer on anything smaller than a 30 gallon. It is SO easy to do water changes of any mass size since the amount of water being changed out can fit in 5 gallon buckets.
 
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Thanks for your input.

I have a twenty gallon tank with very small fragmented hard/soft corals and very little SPS. Oh this tank alone I am having to compensate for around 50ppm of calcium lost a day.

I think we should encourage stability within the reef, and a part of that is dosing. Keeping calcium stable goes towards maintaining the buffer (kh) as well.

I'd also like to tank you for playing devil's advocate but do you really feel it is necessary to provide the side that disturbing the sand is potentially good? Just because someone said it doesn't mean it's good logic haha. Can you offer this thread some rational to why disturbing it could be beneficial. I think it could be of use to me and additional members. I, as of now, cannot think of any.

The biggest point in my thread was to say if you're going to do a water change it should be to remove fish waste. If it is nutrient control we should figure out why it got out of hand and still remove the fish waste. If nutrients is the fish waste is probably pretty excessive..

Also how is a water change "minor maintenance"? And why is 10% the recommended amount? How did we get to this number? The point of this thread is to put an end to the blanket terms such as "10% weekly". I'd also like to say we never want 0 phosphate or nitrate.

What tanks have you been observing where you can say it "it takes one heavily stocked SPS tank to have a major drain on them. " I'd like to say this is far from correct. I have a customer with a 3 week old aquarium with 150lbs of live rock and it's covered in coralline. That algae is actually growing and just sucking calcium out of the water.. I'd open your mind to the possibility these animals that grow a calcium skeleton should receive more of what's responsible for their growth. My SPS tank uses less calcium than my 20g right now hahaha.

"When it comes to those smaller tanks, you are right about those water changes." Am I wrong about bigger tanks in your opinion then?
 
I was just talking to someone last week in the forums that does their sandbed every weekly water change...though the name is escaping me due to the pure frequency of my postings and discussions about.......well everything! The point of them doing so was to get any possibly trapped food or poop that their CUC missed. I personally wasn't able to see past being able to not siphon out the sand! But, I don't advocate this at all only touching on that some live by it.

Water changes aren't minor maintenance, they are a major part of it. I'm saying that it is like playing catch up. 10% is what I was advised by whom I was taught by and man it sure works well. What I learned through my own reef keeping is that once and awhile, for some it could be monthly, that a water change larger than that might be necessary depending on how elements are either produced or depleted. Each system is different, even ones sitting right next to each other.

When it comes to bigger tanks, it can just change the rules some. They bring into play skimmers and other equipment that isn't necessary in the small world. I don't even think there is a skimmer for a tank under 30 that efficient. I don't even think I want to fathom a 50% water change on a 220 gallon to do the work that a protein skimmer will do over time.

And when it comes to use of the elements our reefs need to grow and thrive, of course there are things at play like coraline that will absorb them. I don't want to bring that into play as not all tanks have it. It might be likely that it can, but not all. One of my former go to guys set up a tank that got overwhelmed by coraline in a month. It took years for it to actually get a foothold in my tank...it varies. That even brings into play other things we introduce to our systems that most might not. I have three small mangroves growing in my system that have an impact on the mag in the tank as it absorbs the stuff slowly (as well as small amounts of nitrates for that matter...just not enough to notice). I don't consider that on the draining effects in others tanks because most people don't try to keep them because of how poor of nutrient removal they are and how much maintenance they require.
 
I see whatchre saying.

I'm curious if former go to guy tank went crazy with coralline because he was dosing and yours took longer because you weren't dosing?

It is true corals and coralline will grow at the rate calcium is introduced. My tank is used to getting these levels now. So a lot goes to speak about corals growth rate and need for element replenishment. I'd always encourage dosing for more growth, but if your not looking for the quickest growth it is true many softies and some hard skeletons will slow their rate of growth down. They're smart animals haha. I suppose there's pros and cons to dosing. A Pro higher growth rates and better coloration (probably) - A Con a need to now maintain dosing and watch tank more.

So I can see for those looking to be less involved with their tank dosing can be a pain. But 2-part dosing is so easy. It is as simple as providing the tank with like 5-10ml of two liquids. Do it after brushing your teeth. IF you don't have ATO top off at this time too. It can be made easy and benefits will be noticed within initial weeks.
 
Nope. No dosing. He only lived by one thing, something that I picked up on the use of, and that was Kent's salt. I'm only now trying a different brand because it is kinda low in alk...
When it comes to dosing, I don't suggest this to any type of beginner. It is too easy to throw things out of whack and make things worse. The key in this hobby is patience and stability. No dosing took a birds nest the size of a baseball to one the size of my chest in a handful of months without it a drop of calcium/alk/mag.
Though I advocate against dosing unless your water changes can't keep up with what is being removed weekly by your corals that doesn't mean that I don't have the means to do so sitting in my house as we speak. I haven't even mixed together the calcium/mag, but the alk I use on occasion as over time I need to do so as the weekly water changes from the Kent's low alk salt mix isn't able to keep up with it. This isn't even a monthly thing, but one that can become necessary in my system...one that hopefully can be resolved simply by changing salt mix up some and possibly returning to using whatever salt mix is on sale.
 
No dosing is just lazy in my opinion. Anyone who is not willing to perform a simple tritiation to ensure stability of their eco-system should be asking themselves why they are not. I assume the reason behind your no dose stance would be no testing before hand.

It's also pretty dang hard to over-dose a 2-part system. Even if you dosed it every day your tank would eventually adapt and begin to utilize all of it. Obviously if you have 1 coral you shouldn't dose yet... What's going to get out of whack with a 2-part dosing option though? Everything is supplied in a balanced ratio. And I mean unless you start to get around 8 Meq/L KH, 550ppm calcium, and 1900ppm mg you're not really over-dosing.... So it's really hard to get things out of whack with a 2-part. You really don't even need to test if you have enough corals.

You should be able to just tell by coral growth how much they're using. I think most hobbyist are scared to dose 5 liquids a day because they just don't know what those chemicals are responsible for and how to just look at the tank and see their effectiveness.

EDIT: I also mentioned in the original post how relying on water changes for your hard corals will likely be negative for your live animals as it is very easy to get too busy or forget to do the required water change. And to the same line of thinking you had around water changes slowly picking at nutrients, at this point water changes only slowly re-supply the tank with needed elements. It's more often a tank relying on water changes with hard corals for elements will eventually suffer from low magnesium or low calcium... Very typical for them to also run out of trace elements. Most aquarist do not know you should dose trace elements in combination with calcium..

Sometimes it's just easier to dose a balanced equal portions 2-part system like Seachem Fusion or B-Ionic.

Most of the time aquarist are just too scared too dose. After it becomes a simple method it'd hard to believe it was never done. Especially once the benefits are clearly seen.

You'd be amazed at the growth results you'd get from a calcium reactor or a multi-day dosing auto-dosed

Do you use kawlk for top-off or do you really expect water changes to always be enough?
 
Right now I don't need to do anything besides the occasional dose of alk to get the levels back up to normal. Once I rid myself of that massive birds nest things squared back away pretty quickly and then my coraline growth increased. Adding things isn't necessary for this system, though for the one that comes after it I can only hope to be in a position to need to do it.
 
And are you testing your levels or just guessing? I'm curious if you would even notice if your elements dropped to say 1200 Mag it just happened to be when you did a water change and the negatives hardly if even showed.

You could get away with this poor treatment for a long time but doesn't mean it's right/good.

Dose just carbonates? Wouldn't that result in an immediate decrease in calcium? What's the thought process there? Why raise the carbonate buffer if you're not going to raise calcium? I know Kent salt has very high calcium but none the less it'd still drop calcium immediately.

If your Alkalinity is dropping that clearly means your animals are growing(have a need for elements) or you have a dirty tank... If you still ever need to dose KH up this would imply your water change didn't do enough for you?

So it would be correct to say if you use Kent Marine salt you need to dose because Alkalinity doesn't match up to the nearly 550ppm calcium.. Relying on this salt mix alone for the carbonate buffer would be risky?
 
I test pretty frequently and keep track of all the results. And things are doing pretty well all things considered.
Saying that relying on a salt mix can work. In my case with Kent it is almost good enough, but that wouldn't be the case with everyone because every tank is different.
 
Ya know, a lot of the "issues" you mention with disturbing the substrate are rather conveniently handled by the use of a good old fashioned gravel vac.
What is neato about it James, in case you haven't seen one, is that it allows you to siphon out water AND the detritus in the substrate WITHOUT it going all through the tank and has very minimal impact on water quality.
I've been doing it that way for 40+ years in fresh and salt with everything from a 2' nurse shark to a reef tank.


and what about the guy, Paul B., who has maintained a reef for over 40 years and he regularly runs a DE filter on it stirring the sand bed, and he has one of the most successful reef tanks known to exist, certainly one of if not the longest running one.
He also employs a reverse flow undergravel filter, another supposed "no-no" in reef keeping.


I'm also curious about how many years you have been keeping wet critters.
While your ideas are good general advice, it sounds as if you are reciting learned rhetoric rather than speaking from years of experience as a lot of people you tend to disagree with are relaying years/decades of experience.
 
Well, my fish poo doesn't stick around long enough to need to be cleaned out honestly. I have high flow so my big fish like my trigger that poops almost a powder doesn't cause me issues because the stuff breaks up and floats into my filter socks or is skimmed or eaten by coral. You can't visibly see a single turd in my reef ever. Between my sand sifting goby, my clean up crew and my filtration the poo doesn't need to be sucked out by water changes. I water change to replace trace elements really, my filtration and stocking keeps my water and tank really clean...
 
My Snowflake moray eel sturs up my sand daily. I have asked him not too but like my wife i get constantly ignored.


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I'm also curious about how many years you have been keeping wet critters.
While your ideas are good general advice, it sounds as if you are reciting learned rhetoric rather than speaking from years of experience as a lot of people you tend to disagree with are relaying years/decades of experience.


I'm guessing only a few (less than 10 years) years of experience, so basically only seen the "new" ways of doing things. Doesn't really matter to me though. I won't say that is necessarily good or bad, but it almost seems at times like it is a quest to simply put down experience just for the sake of argument.

I'm a believer that there is some good and bad any way you go when utilizing old versus new practices.


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In a 60g tank a 50% weekly water change is going to cost around $120 a month! DANG! Liquid dosing isn’t even that much and dry powder is even cheaper.

Only if you are being ripped off by a store that charges the extortionate price of $1 per gallon.
I change on average 20 gallons a week and it costs me less than $40 a month.
My system is a 50 display, 5 gallon refugium and about another 15 gallons in the sump system.

If I mix my own it runs roughly .45 a gallon.
(.25 per gal for RO/DI water/ .15-.18 per gallon for salt)
buying it at the store costs me .49 a gallon.

why would anyone pay a buck a gallon????
 
The same reason people would pay for chemi-pure products or even someone to come and maintain the tank for them. It is EASIER for them. Everyone will apply the KIS effect, it will just look different for each individual. Some are successful with it...others have glass cubes full of algae.
 
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