I’ve read about dangers of a large water change in freshwater tanks, mostly due to nitrogen bubbles from the water being compressed. Is there a danger with saltwater tanks if using pre-mixed water? More specifically, is there any chance of a large drop in the nitrate level being fatal to fish? Opinions are welcome!
Joe
how large are we talking? i would think a 25 % change would never afect anything. a 50% may cause a semi cycle. but feel it should stablize parameters in moderations. as you know i am not good with testing but do water changes as regular as possible.
i have changed 90% of the water in m tanks before with no ill effects. just make sure the water replaced is exactly the same as the water replacing.
i have changed large amounts of water without problems as well. i don’t think you’ll get a cycle from a water change done correctly, since your beneficial bacteria is on your surfaces, not in the water column.
That’s what I thought, just wanted to get some more opinions first. I will change about fifty percent this weekend.
make sure your TDS of the water is 0, that would be alot of water to replace with high TDS
hehehe My TDS has never been measured. I suspect that it is somewhere around 250-300, but that’s just a hunch.
thats horrible TDS, mine has risen to 22 and im buying a new DI for my RO/DI system to hold it over till i replace my ro membrane
I have a strictly tapwater policy for my tank. This will be the first water change I’ve done on it since its inception. Fish only tanks are the best bet with new babies and so on. I may fire up a nano sometime soon, though. I keep feeling the coral itch again.
aren’t u worried that u will have a horrible algae bloom that yr grazers and tangs and whatever else wont be avble to get rid of?
[quote=“Jocephus, post:9, topic:2593”]
I have a strictly tapwater policy for my tank. This will be the first water change I’ve done on it since its inception. Fish only tanks are the best bet with new babies and so on. I may fire up a nano sometime soon, though. I keep feeling the coral itch again.[/quote]
that is only 1 of the many reasons to not use tap water, let alone the 2,400 known cancer causing agents in public drinking water, people think its clean, in reality its just “levels less than dangerous to people”
we can also get sun burned but corals cannot, nor fish.
just something to think about.
i’m against tap water in aquariums. i just want to make sure you readers know this. and now for the story-
i built and maintain a 150 gallon in-wall tank at the gym around the corner from me.
i talked the owner into purchasing a R.O.D.I. but he will not let me plumb it in. it sits in the box a year later.
i initially filled, and to this day, top off the tank with tap water with some “prime” in it. for a while i was bringing buckets of water from home, but that got tiresome.
anyways, my point is, that tank looks freaken spotless. no algae at all. it’s a reef. no sps, but alot of hardy zoas, mushrooms, GSP, a bright green sinularia leather, and a nice galaxia colony that seem to enjoy their home.
4 x 150 watt halides and 2 x 54 watt t-5 for actinics.
i never checked the T.D.S. of the water coming out of the faucet there, but as i said, it’s a 2 minute drive, and my T.D.S. is 255 before the filters.
LOCO<
I’m not saying everyone should go dump their RO/DI units, but I don’t have any algae growing in the tank(excepting for coraline). I have 90 gallon tank with a two bulb NO light, a Seaclone 100, and a filter sock in the sump. It houses four fish: a yellow tang, a maroon clown, a clown trigger and a pajama cardinal.
I’m a little scared to do a water change because it has been going so well without. I set this tank up last summer. As I said, fish only tanks are much less labor dependent.
TimH07- What were you getting at about corals and fish cannot get sunburned? You lost me a little. Good link, BTW
oh i was making a comparison (a bad one at that) that what wont kill us can kill the corals, like getting sunburned.
the fact that there is even traces of copper in tap water is enough for me not to use it, over time even with water changes the copper bonds with aragonite/calcite surface and cannot be removed so with every water change over a long period of time you’ll get copper deposits enough to kill inverts and make the tank unusable.
like i said its a tiny amount of copper in tap water (not like throwing a penny into the tank) but over time its going to accumulate as its not removed with water changes.
very interesting tim.
but read the ingredients of the salt mixes and fish foods…there is copper in just about everything we use. as stated, it’s been a year since that tank has been assembled, and everything flourishes. how many years is it going to be before enough copper has built up in the tank to start seeing adverse reaction?
well, far be it from me to change a heated debate here… but to answer your question joe, i dont see ANY danger in doing a 50% change as long as the new water params match the tanks… (minus nitrates of course) i just did a 30 gal change on mine this morn. (come to find out, its more like 14%… which was kinda dissappointing) but i added the water directly to the sump 5 gal at a time and let it mix… pumped some into the tank, then added another 5 gal to the sump and repeated. just so as to mix the water with tank water as much as possible prior to putting it into the display. if u dont have a sump on the 90… add a few gallons at a time with a PH circulating as u go. take an hour or so to fill it back up. wont hurt anything imo. prolly more precaution than necessary really. esp with the hardy fish that r in the tank.
Tim- thanks, I’m a bit slow sometimes. This tank has no corals, but as far as accumulating copper, I’ve never really thought about that. It seems like it would be possible over a very long time.
BJ- Thanks, that is what I figured, just wanted to be sure. And you are correct, I keep bulletproof fish. I top it off about every three days, so I know that the salinity swings are huge. Everyone is fat and happy though.
Yea i wasn’t saying anyone should or shouldn’t do anything, i was just pointing out some of the concerns that i personally have with unfiltered water.
[quote=“Mr_X, post:16, topic:2593”]
but read the ingredients of the salt mixes and fish foods…there is copper in just about everything we use. as stated, it’s been a year since that tank has been assembled, and everything flourishes. how many years is it going to be before enough copper has built up in the tank to start seeing adverse reaction?[/quote]
you are right about trace copper in things like salt and that can have the same effect i mentioned but tap has way more than our salt mixes and it would take dramatic time, i have no data to estimate a timeframe, but i’d guess like 20-30 years to be detrimental. maybe someone should start a study! cough someone with nothing to do cough 
ironicly we have no idea what true copper levels USED to be in the ocean but match the element in salt mixes assuming thats what it should be. turns out bottom paint for boats/ships used to be copper paint designed to leach off in the water to keep barnacles and other inverts from sticking to the hull, a practice that has stopped in most places but was practiced as late as the 90's. all that copper over years has just added to the natural levels that we don't know were previous to human interference. (my friend used to be a charter captain in the 80's and used it himself)
on a side not, it just sucks that the ocean, having more species than land, is the earths toilet these days 