how much is TOO MUCH of a water change?

i'm used to freshwater, and i know i used to do 50% weekly, when the min was 50% monthly for my overstocked african cichlid tank.

i know 10% weekly for saltwater is recommended, but i've been doing 20-ish% weekly.

is 30% too much? i hear the bigger the better, i'm asking because i think i'm over feeding a little and i'm seeing about 10ppm nitrate by the time comes around to do my water change.

is 10ppm dangerous? i have alot of snails and a couple shrimp, i know they're sensitive to nitrates, but seem to be doing fine...

 

Nothing wrong with 30%. Especially if trying to lower nutrients. Just try to match up alkalinity ,salinity and temp. What skimmer and tank size?

 

10 ppm of nitrates isn't gonna hurt anything

 

If that works for you.

What you do not want to do is wait 3 months and do a large water change. Routine water changes are fine.

I used to go by the old 10% bi-monthly.

 

55gal tank. after sand n rock, its oly about 47gals of water.
i was gonna do a 15-ish gal change today.

reef octopus bh-2000 skimmer. supposed to be good for up to 208 gals or something, i'm kinda confused on that. i bought it online, which stated that it was for up to 130 or something, but then when it came the box said for up to 208?

 

I did 5 gallons weekly on my 55 gallon. Never missed a water change for the 3.5 yrs it was running.

 

impressive commitment! i cannot say i have been so keen to follow that strict of a regiment! personally, there have been times I've gotten away with 10% every 3months, but I didnt have a very demanding bioload.

+1 I like Corailline's advice, "I used to go by the old 10% bi-monthly." Pretty solid, and not too demanding as far as time goes!

 

After tank is stabilized.. Personally I shoot for 15% every two weeks. Could be a little more or a little less, that just happens to be the size of the trash can I use. I do think my tank looks a little happier with water changes than without.

I think your said your tank just finished cycling in another thread. It's normal for nitrates to go up for a month or two then they should just come down on their own.