How often do you do waterchanges on a large aquarium? (120+ gallons)

[STiTCH87]

I'm contemplating starting a project build late this summer/fall and building a large tank in my fiance's basement at a size of atleast 120 gallons. Was just wondering, I assume you don't need to do a water change as often on a larger sized tank. So how often would you do a WC on a 120 gallon? On a 200? 300? I do one every 2 weeks on my 29g but i'd imagine a 75 gallon WC twice a month would be rediculous.

Just a general question to answer my interest.

 

[Edward]

I do weekly 10-20 gallon water changes in my 90...My total volume is around 120gallons right now with my sump and soon to be around 150 with my new fuge.

 

[mandrake]

I do 5 to 10 gal. per week on my 120 with 30 gal. sump ( 100 gal. of actual water).I find keeping it small it is not such a chore and I am pretty good about it.

 

[STiTCH87]

Not bad. So if I owned an RO/DI and bought my salt in buckets I could probably keep WC prices under $400 a year i'd imagine.

 

[delta]

Once a week 25%, when I am on target.

 

[STiTCH87]

How on earth do you afford 50 gallons of saltwater per week?! :-O

 

[JayM]

I try and do 10% weekly, when I am on target....and it's 50 gallons too. It's a quarter of a box, about 10 bucks. That's not even 3 gallons of gas these days

 

[delta]

How on earth do you afford 50 gallons of saltwater per week?! :-O

It only cost me $14/week, most spend that on coffee, my tank deserves at least that.

 

[badlands25]

You can probably find an ro unit here on the forums. I bought mine for 75$. Then get a 35 gallon bucket make your water ahead of time and its eazy! I do 15 gallons every other week.

 

[mnavick]

I have a 150g DT with a 90g&55g fuge/sump and every two weeks I do a 55g water change. Always looking for a deal on IO to support this

 

[jenreef]

i have a 120 gallon tank with a 55 gallon sump and a 30 gallon frag tank and my target is a 15 gallon water change weekly. but lately i've been lazy so i have been doing a 15 gallon water change every MONTH

 

[jay2941]

i have a 125 and 75 plumed together for 5 months and do 35-40 gallon water change every 2 weeks. i am in the middle of upgrading to a 325 and plan on doing 50-55 gallons every 2 weeks on that tank.

 

[STiTCH87]

Interesting numbers everyone! I have seen salt sold in immense bulk before. Anyone ever go this route? I know SeaChem salt is sold in huge barrels (I wanna say 50 gallon drums maybe?)

 

[STiTCH87]

Oh and even better question; what do you guys do with all that old saltwater? Please tell me you don't put it down the drain and into metal pipes and septic systems. Lol.

Cheapest on IO i've seen is $57 with shipping for the 200 gallon and it's the Reef Crystals they have on Amazon.

 

[Edward]

Honest?

I have land behind my mother's house that cant be built up because there are town electric/water/sewage line and is lower than the rest of her property AND there use to be a railway that passed through there and the track had something to do with the woburn tanneries so the soil isn't recommended for use to grow edible crops. I just dump all my water there...It's kind of eerie to be honest because all the trees/saplings/bushes that are everywhere else behind there stop where the line you to run through even though it hasn't been there in years. I figure something else is keeping things from growing just there so me dumping a little salty water in a barren patch won't hurt.

 

[STiTCH87]

Very convenient to have such a spot available to you! Lol. I dump mine over my stone wall every other week. And the trees and flowers seem fine to me. :shrugs:

 

[mnavick]

As I mentioned, always looking for a great deal on salt. Krystal Clear in Auburn I think is at $45. Water World in RI I beleive is still doing the buy 1 at $37 get the 2nd half off.

My water goes into the woods. In the 8yrs I have lived here no ill affects.

 

[mnavick]

Hmmmmmmmmm every time I try to edit the double "the" it lists only one, but clearly there's two. Sorry to jump off topic.

 

[Platehead]

Krystal Clear in Auburn has a 200 gallon box of Kent Reel for $42. I do 5 gallons a week for my 29 gallon tank, so it should last me a while. Water paramers very stable with the Kent.

 

[STiTCH87]

You say Water World in RI has a 200 gallon box for $37 and half off the 2nd? Or am I misunderstanding?