Water changes

[slandis3]

So how often do you change your water and how much do you change at a time (what parentage do you change)?

[Todd W.]

Depends... 2 or 3 weeks.  I do about 20-25g on a 90g with about a 25g sump/fuge.  Or more gallons immediately if my parameters get out of line.

[slandis3]

I am starting a new plan. I have been doing weekly 40g changes but a lot can change in a week and I tend to forget about the tank so...
I am now changing 5g a day and twice a week doing 10g changes in place of the 5g changes. Thats an extra 5g of water a week plus that gets me to look at things a little closer.

[METZCOOL]

2 gallon daily all automated, I mix saltwater once a month and get 60 gallon a month changed out.

[DarinSchmidt]

Have you ever monitored your water levels to see if it is even necessary to do so many water changes on such a large tank? I monitored mine for about 4 months doing water changes here and there and figured if i dose a few chemicals, i'd save a ton on salt compared to what the chemicals cost. So I typically do water changes once every 2-3 months depending on the water quality and i havent seen a negative effect on the corals. I do about 100gal changes though when i do. But that was with my Skrubber also because it kept my parameters in check and i was dosing chemicals to make up for what the corals and clams use.

[HUNGER]

i just do a 45 gallon change about every 2 weeks

[starfishprime]

I have a 38g system and I change ~ 10g a week to 2 weeks, works great for what I have.

[Sunny]

Ours has been set up about 3-4 months now. We were doing around 45-50 gallons a week.  The past month we were doing every other week.   I'm going to go to every 3 weeks now and see how it goes.  I will dose on the weeks I don't do water changes.

[slandis3]

Have you ever monitored your water levels to see if it is even necessary to do so many water changes on such a large tank? I monitored mine for about 4 months doing water changes here and there and figured if i dose a few chemicals, i'd save a ton on salt compared to what the chemicals cost. So I typically do water changes once every 2-3 months depending on the water quality and i havent seen a negative effect on the corals. I do about 100gal changes though when i do. But that was with my Skrubber also because it kept my parameters in check and i was dosing chemicals to make up for what the corals and clams use.

yes and as sps and other calcium hungry corals start to really drain your calcium and alk levels. I would rather "waste" money on salt to know I am keeping my water fresh than take a chance on not doing changes and something going wrong. When something goes wrong on a large aquarium it takes a lot to get it back right. 

[Todd W.]

A year ago I was so busy with school and work that I didn't change water in my 46 or dose for about 4-5 months.  I didn't even hardly look at the tank except for feeding the fish.  There were few snails and the algae covered the walls.  I finally cleaned the glass and all my coral looked amazing.  I didn't touch the tank and things looked better than they ever had.

[slandis3]

I think it also depends on what you have in your tank. Some lps and softies are great filter feeders and really help maintain the water.

[micki]

Right now I'm doing 100 gllong every 1-2 weeks unil I get my Po4 and Nitrates under control.  So far it seems to be working.  I hope to go to monthly changes.

[slandis3]

Yea there's another problem, if you don't do water changes and your Po4 starts to creep up it can get into your rock work and cause havoc getting it back out of the tank. 

[micki]

Yes, I am a victim of this...  Things are much better in the Po4 department.  1.38 down to .31!

[slandis3]

sweet

[Boonjob]

I did bi weekly changes at 20-40%...

I had bad phates from the rock though, it seems like it worked nicely.

My new tank is going to have an automated system as well, though it won't be daily, it will most likely be weekely-biweekly...

[DarinSchmidt]

PO4 can be taken care of with a simple algae skrubber, i been using it for several years, when i can get some more time I'll be putting it back on. Never had issues with PO4, but i check my water quality at least once a month and if things look a little hairy, then i do a water change, other than that, i just dose chemicals (calc, alk, mag). Never had to worry about PO4 issues or anything. But on average, i do a water change every 2-3 months, longest i went was 6mo because i had thought that i did a water change one month but later found out that i didnt, never had any issues.

So by NOT doing water changes, it depends on HOW you maintain your tank.

[Boonjob]

Though the chemicals we test may be where they need to be, it may be beneficial for some to still do a W/C

I was told that waterchanges aren't always just for getting water where it needs to be as for nutrients, but also to freshen things up, it was compared/explained to me that our tank water would be similar to the air in a small room with a toilet with a handful of people in there and they can't leave, they eat sleep etc all in this room. The air is going to get pungent no matter what you do, though it is breathable and able to sustain life, it will have a "funk" to it... to remedy this we open a window(water change) to freshen it back up.

Not saying either way is right or wrong, but I try to do a w/c atleast once every couple weeks.

[slandis3]

You realize that a water change puts more back into the water other than calc, alk, and mag right? It also adds strontium, Molybdenum, iodide and other elements. If you are running a fish only or maybe  softies/ lps tank this stuff probably doesn't matter as much. If you have mostly SPS they require a lot more attention and up keep. No matter how well you maintain your tank, if your corals are pulling out all the elements and your not replacing all of them at some point your corals are going to suffer. I guess it really depends on the type of system you want to maintain. 

[DarinSchmidt]

Yes, I'm not recommending this for smaller tanks less than 250gal, but it also depends on how many corals and such of course but for our larger tanks it takes longer, depending on what you have for you to run low on those levels. That's why I asked if you have monitored your levels to see if it is needed for so many water changes. I have monitored mine, though not iodine, and occasionally ill dose strontium, and such which has iodine in it but hasn't been proven if its needed. But anyways it depends on your tank, mine does well with less changes and dosing which saves me a few hundred a year, that's why I figured I would mention it. Not saying you are wrong in doing what you are doing.

[Ashlar]

Not everything that can cause problems is something we measure for- secondary metabolites, allelopathic compounds, turpenes, caulerpenes (if you have caulerpa in your fuge)..

The solution to pollution is dilution- I change about 30g every two weeks on my system that has about 160g of water.

[slandis3]

The solution to pollution is dilution-

+1

[DarinSchmidt]

Not everything that can cause problems is something we measure for- secondary metabolites, allelopathic compounds, turpenes, caulerpenes (if you have caulerpa in your fuge)..

The solution to pollution is dilution- I change about 30g every two weeks on my system that has about 160g of water.

Which means that you are doing about 2gal per day, which to me sounds reasonable, slandis3 is stating that he does 5gal every day and sometimes 10gal on some days. I was just wanting to know if he measured things to see if it was helping improve things.
I do 100g every 60 days roughly, thats close to 2gal a day. I was thinking of doing 50gal a month, or i have a 33gal tub i was going to do bi-weekly.

[Boonjob]

2 gals a day on a 160gal tank is the same ratio as slandis 5 gals a day on a 400gal tank(even though I think his total volume is higher than that even)

[DarinSchmidt]

oh yes, i wasnt taking into consideration total water volume....