Crashing Tank

[SkiFletch]

Well, although I don't have written articles to bolster, Anthony Calfo, Eric Borneman, and Dr Sanjay Joshi all told me that doing 100% waterchanges is both perfectly acceptable and in fact even desireable if a significant nutrient or toxin problem exists within the aquarium. They cautioned that the water should be fully aerated and mixed for 24 hours and that the salinity and temperature should match that of the old water. The article linked above cites caution in doing a 50% change due to temperature and salinity differences... Of course, if you ensure the two are the same, there's no reason not to do 100% changes.

 

[sophos9]

Doing 100% waterchanges is both perfectly acceptable and in fact even desireable if a significant nutrient or toxin problem exists within the aquarium. They cautioned that the water should be fully aerated and mixed for 24 hours and that the salinity and temperature should match that of the old water. The article linked above cites caution in doing a 50% change due to temperature and salinity differences... Of course, if you ensure the two are the same, there's no reason not to do 100% changes.

Hi Ski, totally agree with you and other references I have read agree that in exceptions, 100% changes may be necessary.

Is SG, temp and dissolved oxygen level the only variables in the entire mix that will shock fish?

If you are changing water to maintain trace profiles then surly 40% is excessive and can cause unnecessary stress for inhabitants... This article by Brightbill explores the maintenance changes made, it concludes that with the correct dosing, 10% a month is fine (Muzzy from ultimatereef does not do water changes due any more and look at that stunner)

In light of the recent research with the salt problem, I have to hold my hands up and say that the 10% per week I've been doing does little in removing nutrients for the tank!!

 

[SkiFletch]

Yeah, it does seem sg, temp, and you can make a case for disolved O2 (or perhaps more like lack of dissolved CO2) are the main parameters. Think about it rationally for a minute. Taking sg/temp/O2/CO2 out of the equation, what's left? Magnesium, which is inherently above 1100ppm in almoast any salt I know; Calcium, again, never low in salt mixes; Carbonate and Bicarbonate (alkalinity) again rarely low enough to be dangerous; Trace elements which have no bearing on fish health; Nutrients, which if anything are good to be lower... The presence of calc/alk/mg in salt mixes (once fully mixed) is totally cheating when you think about it. Our water is buffered for us by the salt mix to prevent big pH swings common in freshwater environments.

 

[Danno]

Oi....anywho. My GSP decided to greet me this morning

I think I might have beaten the crash just in time to save some of my corals.
...

 

[norite]

That's good to hear!

If I may just stick my oar in here....40% water changes every week does sound really excessive to me (and expensive!). And why have you decided on 40%? When you mix up a new batch, do you let it mix for a day, or do you just mix it and put it straight into the tank? Freshly mixed seawater is actually quite volatile, and I'm just wondering if this is the cause of it all?

I change about 15% of my 120 liter aquarium water every 3 weeks or so...

 

[Danno]

Indeed, I mix all of my saltwater ahead and put an airator in each bucket and let it sit there for about 24 hours. Sometimes it may be 30% or so.