10% water change...tank volume or tank and sump...?

[Kona26]

I am trying to find what my % is for what my water change should be....I am just trying to figure if I need to add in my sump volume or not. I have a 120g and about 25-30g in my sump.

[Kona26]

I would say 15g every other week would be good...I have been doing about 20 a week...but am thinking that is too much

[homegrownREEFER]

I would say there isn't an exact amount, but we'll see when someone more experienced chimes in. I have a 75 + about 15 sump and I do 5 gallon a week, I have a small load and nothing that really eats up nutrients like corals yet. I think it would more depend on your water quality + if your livestock/corals are using nutrients. Basically what a water change is for; replenish nutrients, lower ammonia/nitrite/ate, and if you siphon dietritus out.

[Kona26]

yeah...I don't have much bio load either...I just trying to get a round about figure so my water changes are about the same every time I do them...and if I need to bump them up I can. I would like to find a gallon counter so I know how much I am taking out....I have a pump in my sump that I turn on and pump it down my drain in the garage. I was thinking about filling out 5g buckets to get an idea of how much water I am taking out

[homegrownREEFER]

What you can do is when you shut off the pump on your tank to pump out your water from your sump, pump it the first time into 5 gallon buckets (I would only do like 2-3 if you have a small bio load) then when it's pumped out mark the water level on your sump with a marker on the glass. This way next time when you do a water change when the water level hits your marker you know it's 10, 15, etc gallon.

[Speed]

Originally Posted by Kona26

I am trying to find what my % is for what my water change should be....I am just trying to figure if I need to add in my sump volume or not. I have a 120g and about 25-30g in my sump.

10% of total system water volume. so in your case you have a total system water volume of approx 150g (including sump)
you should be removing 15g.

[Kona26]

Thank you for the info...That is was I thought...but I kept over thinking it.

[ca1ore]

Agree that you need to consider total system volume.

[trinidiver]

Originally Posted by homegrownREEFER

What you can do is when you shut off the pump on your tank to pump out your water from your sump, pump it the first time into 5 gallon buckets (I would only do like 2-3 if you have a small bio load) then when it's pumped out mark the water level on your sump with a marker on the glass. This way next time when you do a water change when the water level hits your marker you know it's 10, 15, etc gallon.

That's how I did mine also. I have a 200+ gal with 2 - 30gal sumps, and I change 50gal at the end of the mth. I bought one of those brothers label makers (Staples) and put markings all over my sump - "regular water level", "50Gal mark", "Water level-main pump off".........etc. Also used it to label every item and plug. Easier for me and my wife. Made live very easy. I dump water back into the display though, that way, the new water is mixed with a larger volume of water. When it overflows and fills back up the sump, I just turn back on the main pump.

[Kona26]

yeah I figure about 150g .... so about 15g every other week.

[Crooked Reef]

It may actually be more than 10% of total water volume for you. I don't think it will hurt but rock and sand will displace some water.

[nicholasb]

A 5% weekly water change of the total volume is good. If you do it every week then you get into the habbit, and that is good for your tank. A 20% monthly my stress thing out more.!!.

[mkoop]

+1 total volume. I do 10% a week

[Kona26]

Originally Posted by trinidiver

That's how I did mine also. I have a 200+ gal with 2 - 30gal sumps, and I change 50gal at the end of the mth. I bought one of those brothers label makers (Staples) and put markings all over my sump - "regular water level", "50Gal mark", "Water level-main pump off".........etc. Also used it to label every item and plug. Easier for me and my wife. Made live very easy. I dump water back into the display though, that way, the new water is mixed with a larger volume of water. When it overflows and fills back up the sump, I just turn back on the main pump.

Is it better to put the water back into the tank rather then the sump..? or is that just how you do it..? I have ran lines through the wall both in and out of my sump...with my return going into my filter sock...(I always see things floating in my brute)...I thought putting it straight into the tank might shock the fish...being it more concentrated where I have the flow

[Fish Biscuit]

I don't think it matters if you put the new water in the tank or sump. I add mine directly to the tank because for me it's easier & I like that the new water mixes with a larger volume of water in the tank too. It also keeps down the amount of micro bubbles in the display when I turn the return back on.

I usually end up with a random dog hair in my new salt water & so far I don't see anyone knitting sweaters in the tank so I wouldn't worry too much about what is floating in the brute as long as it's not salt that hasn't dissolved.

[Kona26]

lol yeah...I have my water station in the garage...I try and keep all containers closed but always manage to get floaties in my water.

[deputydog95]

I know it's an old thread, but I had a question.

My setup has a total system volume of 112 gallons (includes the display and the sump).

However, the sump obviously doesn't run full to the top and the tank has rock/sand in it, significantly reducing how much actual water is running through the system... Should we be calculating off the total possible system volume, or trying to ballpark how much actual water is in the system after deducting rock/sand/sump level and basing our percentage off that?

[MondoBongo]

Originally Posted by deputydog95

I know it's an old thread, but I had a question.

My setup has a total system volume of 112 gallons (includes the display and the sump).

However, the sump obviously doesn't run full to the top and the tank has rock/sand in it, significantly reducing how much actual water is running through the system... Should we be calculating off the total possible system volume, or trying to ballpark how much actual water is in the system after deducting rock/sand/sump level and basing our percentage off that?

you're probably overthinking this. 10 - 20% change is a great start, but the most important thing is to keep an eye on how your tank is doing. my tank runs best when i do roughly 15 - 20% change every week. i tend to feed heavy, and my rock layout isn't the best for clearing out nasty stuff.

others may do their water change bi-weekly, or even once a month.

so i'd say start with 10 - 15 gallon changes maybe once a week. if your levels are looking good after a few weeks of that, then maybe try dialing it back to once every other week and see how that goes.

for me, i've found it easier to just change massive amounts of water on the regular as opposed to trying to dial back feeding too much. YMMV based on the stock you keep.

[mcgyvr]

These numbers are all rough approximations/generalizations..
Don't waste brain power overthinking..

Some do 10% a week.. Some 20%.. Some 20% a month.. Some 20% every 6 months.. Some haven't done a water change in years..
There is no "right" answer but to adjust/adapt based on knows we can see/measure,etc... each tank is different.

[d0ughb0y]

use estimated actual water volume. Then round up to full 5 gallon buckets if you use 5 gallon buckets to carry water.


say if you calculate 10% to be 8.75 gallons, do 2 5 gallon bucket water change.

[scattered]

Originally Posted by mcgyvr

These numbers are all rough approximations/generalizations..
Don't waste brain power overthinking..

Some do 10% a week.. Some 20%.. Some 20% a month.. Some 20% every 6 months.. Some haven't done a water change in years..
There is no "right" answer but to adjust/adapt based on knows we can see/measure,etc... each tank is different.

You forgot idiots like me who change a small percentage every couple days or even do daily automated changes LOL

As a generality: smaller incremental water changes are better for stability; larger less frequent wc are better for dilution.

[skipm]

IMO people are getting a little too worried with percentages here. You want to change enough water, often enough to maintain your tanks desired parameters. As an example if you change 10 gallons every other week and you nitrates, calcium, magnesium, iodine, etc. levels are within desired levels then your doing enough. However if your levels get way out of kilter and your trying to do water changes to get everything back in check then you need bigger and more frequent changes. Before you do any changes remember to top up your tank to the proper salinity, salt doesn't evaporate and your salinity levels will go up otherwise.