water changes

[Checkitout]

How many gallons per week should I do on a 105g with a 20 gallon sump. I have been doing 20 gallons a week. Do you think this to much or not enough? The tank also has alot of corals in it as well.

 

[Corigan]

Sounds like a fine number to me. I do 12-15 gallons a week on my 70g with 30 sump with good results. However every tank will be different. Do you have nitrate or phosphate issues? If you do then you may want to up it a tad.

 

[Troylee]

it really depends on your bio load and your skimmer.... i change 15 a month on a 225 gal system and it flourishes....if you have a poor skimmer you need to do more frequent water changes imo.....

 

[RBursek]

I agree with builder Bob, it depends on your tank, what salt you use, bio load, corals, I was doing 30gal every 2 weeks on about a 120gal actualy system for about the first 2 years, but then I cut back to every 4 weeks for about a year, and now just setting up a system to do 3/4g every day automaticly, which less more often, is better then alot less frequintly.

 

[kuyatwo]

I do 2 x 5 gallon water changes a week on my 65 gallon tank

 

[spongebob]

my local LFS has a 6 yr old 300gallon sps tank and he does 30% monthly in addition to 10% and has a good skimmer. The bio-load is heavy with about 20 medium size fish and a few large ones. Best tank I have ever seen, flawless and never had an algae bloom or even algae on the glass.

 

[litenyaup]

it really depends on your bio load and your skimmer.... i change 15 a month on a 225 gal system and it flourishes....if you have a poor skimmer you need to do more frequent water changes imo.....

+1 i do 10 gal a month on my 90....skimmer is the backbone...IMHO

 

[reef-nut]

I only have a 16 gallon loaded with softies and no skimmer and I do 4 gallon a week. I am putiing on zoo and paly polyps like crazy.

 

[lazyreefer]

Like Rbursek noted quality of salt is important, we naturally assume WCs are primarily for nutrient/detritus export but just as important is Ca, Mag, Alk buffering, and trace elements addition. So, if you are dosing for Ca and Mag doing WCs can actually hurt if the Ca and Mag elements of that salt are lower than what your tank parameters are. You spend a few days getting your numbers higher only to lower them with a Water Change that has less of what you want.

Along those lines if you're not using RO water then WCs are just adding dissolved solids, phosphates and whatnot - so again you may be using a Phosban reactor or some sort of power filter which gets your phosphates lower but now a WC with water straight out of your tap adds it all back in.

One of the things I'm trying to figure out is the addition of top off water, I'm dumping 2-3 gallons a day of basically inert RO/DI water into my tank, in effect I am doing a 3 gallon water change everyday with distilled water. What can I put in that water to make it a "positive" addition to my tank possibly cutting down on my frequency of WCs....options include limewater, a buffer of some sort, maybe saltwater every third week or something, how 'bout Ca and Mag, I'm sure there are more.

So my long answer to your short question is there are many factors which you should consider when trying to figure out how often to do WCs....stability of the system may be most important of all rather than chasing numbers. How about costs.....you can save some money by buying a salt that has what you want in it thereby cutting back on the need to dose or how much product to dose, potentially cutting back on WCs your system can be more stable, having corals that thrive in a little dirty water, having less fish to make it dirty, (which requires less food = less cost) or adding critters that help keep things clean, and then you got the whole how much time do you have to spend on maintenance, etc....

Sorry to ramble, one thing I have learned that even the simplest of questions has alot of different things to consider. That's why I enjoy R2R so much....

 

[Checkitout]

Thanks to all who chimed in with their helpful tips and info. I guess I will keep up with what I am doing since it seems to be working. Another reason why I do this much is because I never test my water and find by just doing water chages and having a good skimmer is working so far. I basically was just trying to get a little feedback from everyone one what they think and do.

 

[lazyreefer]

Well if it ain't broke, there's probably no need to fix it.....yet

You might want to do some testing, if you are going along for months with a certain set of parameters, then those numbers change it could be like the canary in the coal mine letting you know something is wrong. If you don't know what is "normal" you'll never know what is abnormal.

 

[HighlandReef]

i do ~35 gallons every 2 weeks weeks on my system, 210, 40 sump and 30 breeder frag tank.

 

[Checkitout]

I think the amount of water i change is fine, but i still question if I should do it once or twice a week.