how often should I do a water change

+1000 to this. Nobody matches pH, salinity, and temp 100% perfect when doing a WC. So how in the world does doing weekly waterchanges keep your system stable? I have never understood how people come up with these imaginary WC schedules that magically assure you have a nice tank. Use test kits and your eyeballs. If stuff looks healthy and is growing, why bother?

 

Very good point insanespaun, I will just go by test kits better then doing uneccasary water changes.

 

I agree with this ^

 

5% weekly is the best......

 

Every tank has it's own personality, it's own rate of utilization of trace elements, big 3, build up of DOC, filtration type, replacement water quality type......

No blanket statements will cover each individual tank.

A safe generalization of a monthly or bimonthly change of 5-10% will not hurt a tank nor will it save a poorly maintained system.

 

I am a fan of waterchanges. This it is the single best thing you can do for your reef. I do 10% weekly wc on my 46gal. Everything always looks fuller and happier after I do them and I run skimmerless. Nitrates test 0 and phosphates always less than .1 (dont want 0 as you need a little for the algae in the coral tissue)

I understand the reasoning behind the arguement above stating that if you can maintain 0 nitrate/phosphate without WC than you never need to do them. The main flaw I see is what do we NOT test for??? There are many other things besdies nitrates and phosphates that can build up in our systems, those are just the main 2 we have to focus on. I do agree that if you have a problem or are overstocked than WC will not solve the problem but I would rather be safe and stay on top of my waterchanges than let things go and risk playing catch up later. It also gives me an excuse to put my hands in the tank every week and add a new coral

The second point is repleting trace elements. Although you state there is no data to support the rate they are depleted, there is also no data to support them lasting more than a week. Once again, many things we do not test for either because we cant or it is to complicated/expensive and not the norm of the hobby. This one is hard to r efute because if you have no corals than obviously nothing gets used up, but depending on your stock things will get used up at different rates. I am not going to dose trace elements and risk going toxic since I do not test for them, but a weekly WC will replenish them without that risk since if there are still significant values left in the system they would be removed with the discharged water before being replaced. I rather keep them more stable than allowing my reef to run dry of these trace elements before replenishing to minimal levels. Over time the amount of trace elements left in the system would become lower and lower since you are allowing the system to be depleted and looking for signs of coral stress before replacing them with only 5-10% of what they should be, unless you are doing a 100% water change that is.

Just my .02 but on a small system where the expense on salt and water would be so minimal compared to the price of your livestock, I would take the hour each week to designate to making water and doing a 3-5gal WC.

 

Very good info steeler I will take that into consideration, you are right. With my nano tank it won't be such a big deal for weekly water changes. Im just going to figure it out as I go along, like you guys said every tank is different. This thread sure is helpfull, thank you for all the feedback.

 

I enjoy playing with the tank so my 29 gallon bio cube gets about 5 gallons a week changed.

 

well iv seen people doing 10% WC using redsea coralpro salt in a mixed reef without dosing anything...

 

I am doing 3-weeks wc about 15% and dosing weekly on my 29g nano. I have corals and fish. My water reading is always perfect or close to perfect. My NO3 and Phosphate never go over 0. Alk, Ca and Mag are replenish weekly though with ReefRoid One. Stability is more important than do wc too frequent.

note. I am also using RedSea CoralPro, when wc, and on that week I skip dosing.