It's actually common simple math I'm surprised I have to explain it yet again , what do you remove with %10 water change? Lets say for giggles
You were able to leave the calcium , salt and all other things behind what have you removed ? Nothing more than %10 that's it ....so if you had 20 ppm nitrates you'll now have 18ppm how is that a good way to export nutrients ? Do you think the nutrients are finite? As long as there are animals and organic life there will always be an addition of nutrients so why on earth unless you have an infinite supply of salt or money would you use water changes for the sole purpose of nutrient export ? Get it now?

You used the quote about how using water changes to replenish calcium and alk to eventually become not enough hence the reason to add them your selves whys that? Because the size of the changes and cost would be a waste and considered not the ideal route to go.

Your not removing just nutrients your wasting things that are still good lol

So far I've seen you post an article which you obviously either dont understand or am missing the point of and you talk about trying to be a scam like a lfs well my friend I don't work for a lfs and I also don't take alot of my advice from guys who picked up reefing when myths were the norm lol spend a little time on the Chemistry form ask this exact question I'll gladly cone back for a chat or I'll meet you there I'm on it all the time ;)

So I ask this and maybe you can actually answer it on your own words what does a routine hobby change of 1% a day remove in the way of nitrates and phosphates .....do the math on an easy number like a 100g tank with 100ppm of nitrates and 1ppm of phosphates ....post you math here and let's go over it then tell me how long it would take to get zeros without the fact that these nutrients are created 24/7 and added all the time....no nitrogen no life after all .

I'll be curious to see what you come up with lol

PS. To go back to your article if actually read it you'll see the goal isn't nutrient export it's exactly as I said to replace elements and remove the build up of trace metals of course removing g water will remove the nutrients but if you wanted to keep zeros you'd have to remove %100 everyone so that's why people carbon dose , skim run gfo etc. Not because these things are fun to do or too much money on hand because these things are simply better and way more efficient at doing so .

Cheers

Here's some great ways to lower nutrients and practises used , funny enough I don't see water changes as a primary route to go in fact rhf (pretty sure his words are good no?) Even says in the opening paragraphs that decades ago it was the primary way to remove nutrients but is not the case anymore , we have much better ways of doing so now as the article explains in great detail lol

http://www.advancedaquarist.com/2003/8/chemistry

All due respect, I haven't seen yours.

I use wc to replenish elements not as a bandage. Just saying....lol

How about this. Why would we need to do a water change when my tanks open top and evaporates and I have to top off?😁😣

Because only water evaporates, nothing else.

I think you guys are both right. :lol: I have to kind of agree with Denny, and I kind of agree with you. It's not that water changes are a poor nutrient export, it's just that water changes aren't usually the most effective choice. Water changes for nutrient export in tanks that have a small bioload and are regularly maintained certainly may be the best option. For most reef tanks though, there are often better options - especially if you're using a premium salt brand. This is particularly the case when nutrients have gotten out of hand and you're looking for nutrient export for the purpose of nutrient reduction.

For example, I started doing maintenance on a reef tank with about 750 ppm nitrate and 2.5 ppm phosphate. I'm doing 10% water changes and added a biopellet reactor. We're down to about 500 ppm nitrate now. To further make this point, I recently added some dried out live rock to a tub with RO water. The tub had 100 ppm nitrate and almost 0.5 ppm phosphate. Two 100% water changes later and I have noted ZERO difference in those nutrient numbers. Thankfully I can use RO for this instead of saltwater. If you translate that to the above mentioned tank with 750 ppm nitrate, I could have used 3 buckets of salt to do two 100% water changes and I'd still be at square one. I spend what is equal to 6 buckets of salt on a biopellet reactor and biopellets and I'm leaps and bounds ahead.

On the other hand, my own 50-gallon frag tank at home has a skimmer on it, but no other means of nutrient reduction (no carbon, no GFO, no resins) other than weekly 20% water changes. The tank isn't overstocked, but it's definitely full. The tank is maintained at 2-3 ppm nitrate and 0.08 ppm phosphate which is exactly where I want it.

SO my point is, every situation is different, and a nutrient export program needs to be chosen to fit the needs of that particular tank and also that tank's caretaker.

And here's a 12 year old RHF article to prove you ALL wrong because we knew this shizz a decade ago before we even had voodoo biopellets! :p
http://www.advancedaquarist.com/2003/8/chemistry

Well said Myka and I agree on smaller tanks especially Nanos I prefer the very large water changes and often do not go much further than that but your right there are a lot of variables from tank sizes to animals and the old answer of just do lots of water changes isn't always the best answer anymore and doesn't always apply universal to each situation :)

I hope people reading this don't think I'm against water changes I'm actually all for them just not for the sole purpose of exporting nutrients , the benefits of water changes are certainly much more than that :)

As I mentioned though the main goal is to replenish elements and remove unwanted things like the build up of metals tgat come from mostly foods. When water evaporates and turns into a gas it leaves behind pretty much everything that was bound to it so while water dissappear it removes nothing and replaces nothing :)