I still have high phosphates even with phosphate remover and a reactor but the are slowly going down. Most likely the phosphate are in my sand and live rock from all those years. That is reason enough to do water changes in my book. Lol
Just realize how much money that method is costing you, doing water changes to lower phosphates and using media. Those are in my book the 2 most expensive methods to lower "high" phosphates. You are literally going to spend hundreds of dollars in salt, water, and GFO to accomplish the same thing as $10 worth of plastic and a couple light bulbs to make an ATS. This goes back to what I said earlier about 1001 ways to get the same end results, the way you are doing it will work, but IMO it will take a lot longer and cost a whole lot more than using algae to remove high phosphates and nitrates. RO/DI water is a must IMO though, which I know some others will disagree with me on that (thinking of LA Fishguy). GFO is best used as a "phosphate polisher", not really a remover. If you have phosphates over .10 and use a normal GFO reactor, the media can be used up in as little as 24 hours and in that time it may have dropped it from .10 down to .09 but since it is leaching out of the rocks/sand the next 24 hours it could climb right back up. GFO is best used when there is nothing leaching out of the rocks, and you have less than .1 phosphates and are just trying to maintain a balance. It is good if you are trying to maintain a .03-.05 range, but very costly if used to try and remove large amounts, plus GFO pulls out trace elements.
Aquarium Chemistry: Effects of GFO (Granular Ferric Oxide) on 'Trace' Metals Concentrations in Artificial Seawater — Advanced Aquarist | Aquarist Magazine and Blog
I do monthly because its cheap and new fresh water and elements has to be better than not doing so.
Again, nothing bad about doing water changes at all, just cost $ so I would debate the "cheap" part, assuming you used good water and salt mix. If the goal is to remove bad stuff from the water and replace elements, I have that covered much cheaper than doing it via water changes. Algae to remove the bad stuff, and dosing to add the elements. None of us can test for "trace elements" at home, so I rely on B-Ionic 3 part for replenishing the minor trace elements since it does contain the trace elements along with the major elements (unlike BRS 2 or 3 part). Since I don't run any skimmers I am not sucking out the major and trace elements I put into my water so I don't need to replenish them nearly as much as those who do run a skimmer. I do think one day I will need/want to do a water change in order to get everything back in balance (all those ions) but for now I am waiting until my tank tells me (visually) that it appears to need that, not just do them because it is a certain day of the week/month. I would guess at some point between years 3-5 on my tanks without doing a water change I will at some point need to do a 100% water change on both of them, but that doesn't cost much for me, 1 water change that seldom is a whole lot cheaper than weekly or even monthly 10-20% water changes.
Feature Article: Elemental Analysis of Skimmate: What Does a Protein Skimmer Actually Remove from Aquarium Water? — Advanced Aquarist | Aquarist Magazine and Blog
Ace25 - I am setting up a 75 and would love to hear more about your system -- stock list, maintenance, etc. I am going for lots of fish and low maintenance
To answer your question...at first it was because everyone said I had to and that it replaced essential elements. Now, I do it basically because of the way the tank responds to them. Everything just perks up and looks better. I assume it must be doing something even if I don't understand it all.
My stocking lists are all small fish, no tangs or anything of that size. I have many gobies, blennies, wrasses, clowns, and a multicolor dwarf angel.
My belief on why that happens (things perk up after a water change) is due to inadequate filtration. One may have a $1000 skimmer and 20 different reactors, but if they are missing key parts to filtration it doesn't matter how great the rest of your filtration is, actually the other filtration could be a negative, like the case of skimmers pulling out a lot of trace elements. For me, maintenance wise, 2x a week I clean the glass with a magnet, replenish kalk top off water on my SPS/Acro tank/ATO bucket and dump in RO/DI water on my 60G which has easier corals. Every 7-14 days (when the screen gets full) I will pull out the screen on my ATS's and scrub the algae off. Once a month I will run alk, ca, mg, po4, and no3 tests just to ensure everything is still good.
I do think algae is a key component to a successful reef tank, much more than any other piece of filtration because algae will remove nitrates and phosphates extremely well at no cost, and it also releases stuff back into the water that will feed corals up to a point. Algae releases DOCs, and if DOC levels get too high it can have negative effects on corals, which is why I use Purigen twice a year to lower my DOC levels. I think of using Purigen like using a Super Skimmer, it quickly removes the bad stuff a skimmer removes, but leaves all the good stuff in the water, and does it 3x better than a skimmer could and is reusable. That doesn't mean an "algae scrubber" is required, a good size refugium will do the same thing with a lot of macro algae. We are so focused on removing stuff from the water as a side effect we are also removing a lot of the good stuff from the water with the various filtration methods out there. Skimmers, carbon, and GFO all remove "good" stuff along with the bad stuff, so knowing how to use them properly is key. As an example, in the case of GFO, there is a point where it can remove a lot more good stuff (trace elements) from the water and none of the bad stuff (phosphates), like when you get phosphates below .03 and still run GFO. Same with a skimmer, a skimmer removes way to much good stuff out of the water and very little bad stuff (but it does remove some bad stuff so they are not a complete waste, just expensive on the wallet having to replace all the good stuff a skimmer pulls out). IMO if one uses a skimmer I really feel the best way to use them is on a timer, and no more than 1 hour a day/night. That will remove as much bad stuff as it could in a 24 hour period anyway without stripping too much good stuff out of the water. Here are 2 pictures of my "filtration systems" on my reef tanks. Very simple, just an ATS, no skimmer, no reactors. First picture is my ATS on my 75G, second picture is my ATS on my 60G.
I like my water to look clear with not tint of any sort and it is just better over all for the inhabitants.. Think of it this way the ocean does not keep the same water in the same place for weeks at a time, so why would the corals and fish like it in a closed system. And of course trace element replenishment.
I used to think like this as well, one would think with such a vast ocean with all the currents this would be true, but it actually isn't. Do a google search on "reef nutrient recycling" and you will see that reefs actually clean/recycle almost all of the water on that particular reef.
I want to make it perfectly clear I did not create this thread to promote Algae scrubbers (which is why I didn't specifically mention it in my first post). I use them and think they are great, but a good size refugium with macro algae can accomplish the same results, possibly even do it better due to the larger variety of life found in a refugium vs a plastic screen of algae but a refugium takes 10x more space than an ATS. It took me many years to get that "feel" for my tanks where I can tell quickly if things are going good or bad. Learning the ability to be able to look at your tank and instantly be able to tell if something is going bad, and better yet, to know and understand what that something is, is really priceless in this hobby. To me, that skill above all else is to me the most important thing to grasp, once you have a firm understanding on the various bad things that can be in the water, and how they affect the rest of the tank, then being able to take the proper actions to fix it becomes very easy. If you haven't learned that skill (and it took me quite a few years to learn it myself) then it comes down to the shotgun approach when trying to solve issues. A water change is a good shotgun approach, but adding things like Biopellets + carbon dosing + giant skimmer just because that was the advice you were given from someone on the internet may just cause more issues, like if your issue was Alk related, water change would help, all those other things wouldn't. If you have an understanding on the issue, know that it is alk, then it cost just a few $ for Alk supplement and you are good to go vs the more expensive shotgun approach.
As stated above I do my water changes to remove waste that can build up in the water and to replenish anything that may have been depleted. As stated water in the ocean is always circulating and does not stay the same. In a closed system water changes help to keep things fresh.
