Water Change - Frequency

[dhanck]

I am wanting to get some opinions on this potential water change schedule.

I have a 125 gallon tank (FOWLR), 55 gallon sump (about 30 gallons of water). 0 Nitrite and Ammonia, <5ppm nitrate and 1.024-1.025 SG.

I was thinking about doing weekly 10 gallon (about 6.5%) water changes and then once every 3 to 4 weeks doing a 30 gallon (20%) water change in place of the 10 gallon. I am thinking this will help with nutrients as well as cleaning up the sand, rocks, etc.

I am asking because I see some different opinions like 20% every 2 weeks or once a month, 10% weekly or biweekly.

Also, I am curious because 30+ gallons is a chore and takes a couple hours and I am trying to be more efficient and split it more like 30 minutes each week then a couple hours once a month. I am sure it will become easier over time, but I was hoping the above schedule would work well.

Thoughts? Good, bad, indifferent?

[j.falk]

30+ gallons = a couple hours?

For a tank that size, I would mix up a fresh batch of saltwater in an unused garbage can, aerate it overnight with a power head and heat it to the correct temperature using a submersible thermometer.

Then the next day, use a water pump to drain the tank to your desired amount and then use the water pump to put the new water back into the tank. It shouldn't take you more than 30-45 minutes total to do it that way.

[dhanck]

Originally Posted by j.falk

30+ gallons = a couple hours?

For a tank that size, I would mix up a fresh batch of saltwater in an unused garbage can, aerate it overnight with a power head and heat it to the correct temperature using a submersible thermometer.

Then the next day, use a water pump to drain the tank to your desired amount and then use the water pump to put the new water back into the tank. It shouldn't take you more than 30-45 minutes total to do it that way.

Yes, I am counting making the water the day before as some of the time, mixing, measuring etc.

Then the day of the WC I use a syphon/vacuum to clean the sand and any detritus I can suck up as opposed to just pumping the water out. Then taking the 5 gallon buckets upstairs and outside to dispose of old water. So it takes me a little more time than just pumping water out and pumping back in.

Maybe I am doing something wrong, but still trying to figure out the best way to do it.

[j.falk]

The 5 gallon bucket hauling is where you lose a lot of your time. What about getting a Python to hook directly to a sink to syphon the sand bed and remove the water at the same time? I use one on my 75 gallon to drain it once every two weeks and it works great. Draining and refilling usually takes me 45 mins - 1 hour depending on whether I'm thoroughly cleaning the glass or not that week. I'd also still recommend a water pump for pumping the water back into the aquarium...that saves a ton of time vs. carrying buckets.

[mcgyvr]

All depends on whats in the tank..
For a fish only tank you can get by with far less water changes than if you had corals..

[carrots]

Like mcgyvr says above. "Depends on whats in the tank" It seems that what you are doing is working for your tank, so why change? You could go months without water changes if the fish bio-load was low and your filters could keep up. If my water quality is good, I sometimes vacuum the gravel into a bucket with filter socks on the end of the hose and then return the clean water back into the tank. If I see nitrates rising above 20 I make sure to do water changes. Try backing down on the changes and see how your tank handles it. You may find that a 5 gallon a week water change works just fine for both you and the fish.

[Ron Reefman]

If water changes help you with nitrate and phosphate export and/or keep your Ca, alk and Mg up so you don't have to dose then regular water changes are a good thing. Do enough to keep parameters in line.

If you have a mature system (usually about 1 to 2 years old) and you have systems for keeping nitrates and phosphates under control (reactors or refugium) and you are already dosing because you have a lot of stony corals, then water changes become less important.

I have a 125g DT, a 40g sump and a 50g display refugium. I have to dose Ca and alk as I have a lot of stoney corals and my refugium takes care of my nitrate and phosphate. So in the last 6 months I've done two 25 gallon water changes. Not because anything said I needed to, but because I wanted to!

[kmbyrnes]

I do 2 types on my 125 reef.
Either a half-Brute ( 10 15 gallons ) every week or a full Brute ( 25 -26 gallons ) every other, depending on what my smaller tanks want and need.
Either way, it only takes 15 - 20 minutes for the actual water drain/fill.
I make the water the day before, bring it inside to cool off ( AZ heat ) and do the WC in the AM.
I can spend a couple hours in the cleaning if I get really involved, but the WC itself is fast and easy.

[dhanck]

Thank you everyone! I will continue to keep an eye on the parameters and make sure the water changes are working for the tank!

[j.falk]

Originally Posted by dhanck

...and make sure the water changes are working for the tank!

That really is the key to everything...finding what works for your individual situation. No two tanks are exactly the same so what might work for one person may not apply to everyone else. As long as the livestock is healthy and thriving that's when you'll know that you're on the right path.