My last water change was August 29th.

[Anonymous]

I went out of town for 4 months and left my tank with someone who I decided would be more likely to cause harm by changing water than not changing it.

I realize it was a bit of a roll of the dice, but everything seems fine except my pipe organ coral. I haven't had the nerve to test the water for nitrates, but they were zero when I left.

Due to a bunch of concerns I still haven't changed water in the 2 weeks I have been back. But I am beginning to think it is time.

Is the best course of action to change a little bit every day, or maybe 50% every couple of days? If I want to get rid of pollutants, it seems like at least 3 water changes of > 50% will be required to make a significant dent in anything nasty that has accumulated, but I also don't want to shock the system too much.

Any advice, especially based on similar experience, is greatly appreciated.

 

[Anonymous]

I'd just go with a 25% change per week for a few weeks. They "adjusted" to the dirty water over time, sometimes you need to adjust it back to the clean water the same way.

 

[Anonymous]

3 months is the longest I have ever gone between WC's.

I just went a whole year doing 25% WC's every other month.

My corals are healthy and growing but the coraline isn't what it was.

I think 25% WC's monthly are probably better for your tank.

That is what I plan to do this year.

I'll note the difference and then see what the long term plan will be.

Doing WC's sucks.

Louey

 

[Anonymous]

Why 25%?

Let's say I have 100 ppm nitrate (or pick your poison) and I want to get it down to about 3 ppm.

If I did daily 25% water changes, and assuming I got no new nitrates produced, I would have to do 12 successive 25% water changes to get it down to about 3 ppm.

If I changed 50%, I would "only" have to do five succesive water changes to get it to about 3 ppm.

So if the goal is to get rid of the toxin, it seems like I should change as much water as I can. Practically speaking, I can't drain more than 50% of my tank without creating a really serious disruption.

Maybe I should rig up a temporary sump of equal volume to the tank and fill it with new saltwater, and then change that each day for 5 days?

 

[Anonymous]

I don't remember when I last did a real water change. We give or sell so many frags out of our tank that we bag up a large amount of water each month. We replace it with RO or saltwater when needed. I don't have any algae or nitrate problems and my corals are growing quickly. I am not going to change my schedule. My theory is "if it isn't broke, don't fix it."

Andrew

 

[Anonymous]

I forgot I was talking to an actual scientist type. :lol:

My basic thought is that you don't want to shock the corals too much. Even though 0 nitrates may be the goal going from 50 to 0 in 20 minutes might not work. Large water changes (over 30%) just muck with the pH, alk, and salinity too much IMHO.

 

[Anonymous]

I'd test the water first, and see just how bad things are before you go to the trouble and expense of those large water changes!

I had a tank that hadn't had a water change in three months and it tested better than I thought when I finally got around to doing it.

Because I wasn't feeding the tank or encouraging things to grow I guess the pollution didn't accumulate.

Good luck...

 

[Anonymous]

Is there any evidence that changing say 90% of the water (assuming I could do it without physically disturbing the rocks, corals, etc) shocks anything? It seems like the ocean is one continuous water change.

 

[Anonymous]

Yeah, but the ocean has pretty much the same water quality at all times (it just moves around and provides current). I think you would shock a closed system with a change of that size.

 

[Bucktronix]

why would you start changing water until you know what the paramaters are like.. comeon it takes 10 mins.

 

[Anonymous]

Well, if say pH and nitrates are fine and maybe it is a little low on iodine, am I justified in not changing the water?

We measure only a subset of what is important. I am more worried about accumulated impurities. I lose about a gallon a day to evaporation, so a lot of fresh water got put in.

 

[Anonymous]

Well, if say pH and nitrates are fine and maybe it is a little low on iodine, am I justified in not changing the water?

Nope.

We measure only a subset of what is important. I am more worried about accumulated impurities. I lose about a gallon a day to evaporation, so a lot of fresh water got put in.

:lol: see the above...

 

[Anonymous]

It looks like I'm going to be doing about a 75% water change in the next week or two - I'm draining my whole tank so that I can take all the rocks, pull off the xenia and polyp plagues, put concentrated kalk paste over the affected areas so the plagues don't grow back, and then refill. I have a 300gal and can't save that much water, so I'll save about 70 gal. in the sump, clean the top, mix a whole new tankfull of saltwater for a couple of days, and then put the cutie pies (livestock) back in.

I don't have any paramaters that I can test that are out of whack. I'm a little nervous about that big of a change, but oh well! At least I'll be shocking them with clean, healthy conditions.

Anyone have stories of gigantic water changes gone bad?

jayo

 

[Anonymous]

Although I would never advocate it, I've done both extremes and never had any issues. Went over just a year without a water change in a 55 without any issues (tank had been established for about 3 years at that point) and also did weekly 5 gallon water changes on a ten without issue. I would guess some middle ground would have been better.

 

[Bucktronix]

im sure a water change is in order but until you know what state the water is in i guess you dont know how much to change.

 

[Anonymous]

It looks like I'm going to be doing about a 75% water change in the next week or two - I'm draining my whole tank so that I can take all the rocks, pull off the xenia and polyp plagues, put concentrated kalk paste over the affected areas so the plagues don't grow back, and then refill. I have a 300gal and can't save that much water, so I'll save about 70 gal. in the sump, clean the top, mix a whole new tankfull of saltwater for a couple of days, and then put the cutie pies (livestock) back in.

I don't have any paramaters that I can test that are out of whack. I'm a little nervous about that big of a change, but oh well! At least I'll be shocking them with clean, healthy conditions.

Anyone have stories of gigantic water changes gone bad?

jayo

If your water parameters are fine, then I would worry more about the temperature than anything else. If the water is in bad shape, you may or may not problems.

 

[Anonymous]

im sure a water change is in order but until you know what state the water is in i guess you dont know how much to change.

It is in California.

 

[Anonymous]

Is there any evidence that changing say 90% of the water (assuming I could do it without physically disturbing the rocks, corals, etc) shocks anything? It seems like the ocean is one continuous water change.

Make sure the water is well mixed, with comparable temperature and pH, and there shouldn't be any problems. Did you see my propagation tub thread? Those frags went from established systems to a tank full of brand new (well mixed) artificial seawater.

 

[Bucktronix]

im sure a water change is in order but until you know what state the water is in i guess you dont know how much to change.

It is in California.

i think your target number should be 23% then

 

[Anonymous]

But I would imagine that in a tank setting (live rock, and sand) and change that large would inevitabl;y stir a lot of stuff up. Not too mention there is a lot more bio diversity to crash than a few coral frags.