Adding new mixed saltwater

[jcm1229]

Most people say mixup your saltwater and aerate it for a day before using. What difference is there from say filling a bucket with water, adding the right amount of salt, and mixing (stirring) the hell out of it for 15 minutes or so - until it is obviously all dissolved??

[Hawkdl2]

It depends on the volume of water you are replacing. If you are doing only a 5% water change, it would probably not make a lot of difference. I use IO salt on occasion and have used it within an hour of mixing with no apparent ill effects. However, I use a magnetic stir plate and run a powerhead for that hour or so. I also usually let it mix and aerate overnight (12-18 hours). It is also wise to heat the water to your tank temp.

Water out of an RO or RO/DI system ,or even out of your tap may or may not be well aerated and therefore may be low in oxygen content. If you are replacing a fair amount of water in your tank, it would be beneficial, but probably not absolutely vital, to aerate the water prior to placing in the tank. If your tank has sufficient mechanisms for aeration (skimmer, overflow, etc.) the tank's overall oxygen content will be fine. Also, unless you are mixing the water with a spoon or similar, the salt will dissolve fairly readily.

[jcm1229]

I't for a 37 gallon (~28 gallons water) replacing the amount removed after acclimation.

If aeration helps, Is it sufficient to use one of those battery operated (cheap) air pumps with a stone, or do I need a powerhead in there??

[DgenR8]

When newly mixed salt water appears completely mixed, it's still "raw" Many of the animals we keep are effected negatively by "raw" salt water. The salt needs to be dissloved completely and temp has to match. I believe these two are the most important factors contributing to the "24 hr rule"
Water out of my RO/DI is less than 60 degrees. If you are getting away with tap water, (I don't recommend this) then don't use "warm" water from the tap as your water heater is chock full of contaminants. I run COLD water through my RO/DI and heat it while it mixes for about a day.

[G-money]

Aeration and aging allows the ions to "settle down" so to speak. Basically, we are adding a buffered mixture of ionic salts to our tanks. I aerate the heck out of my fresh batches for two days before changes (of about 1/3 on a 90) and many of my "SPS" pull their polyps in anyway for up to an hour - some more. Whenever I have had to add "quick-mixed" water (even <5 gallons), they pull in for hours or even a whole day. I think there is some form of osmotic shock or aggravation that takes place. I can see the water get a bit hazy even with well-mixed water. (I use IO, FWIW)

We have to realize, these are mixed chemicals we are adding to our tank. They are not of the batch that nature mixed up millions of years ago. Synthetic is the key word.

[Mako]

I pretty much follow Graig Binghams advice obtained from his article How to Mix a Batch of Synthetic Seawater in Under Five Minutes (http://www.animalnetwork.com/fish2/aqfm/1997/sep/bio/default.asp). It's never failed me yet! The Nalgene Prop he speaks of is available here (http://www.usplastic.com/catalog/product.asp?catalog%5Fname=USPlastic&category%5Fname=Syphons%2CSamplers%2CStirers&product%5Fid=Stirrer%2C+Nalgene+%28R%29).

HTH

[G-money]

Mako,

I forgot about that article...curious as to how much you have mixed gallon-wise and how big of a drill you use (or need)? I mix my water in a 33 gallon tub that is over 3' deep. The stirrer is only 18", so I am not sure how well this would work for me. That's why I never tried it. It is ideal for smaller batches, though.

[Mako]

Well, I use a rubbermaid 32 gallon trash can when I mix. Most times I am mixing to the capacity of the can. I use an old 1/4" Sears drill with the nalgene prop. The prop is only 18" long so it does not reach to the bottom of the can. Usually I have the drill running full speed when I pour in salt and then I will reverse the drill to push water to the bottom of the can to get any salt that settled. It works really well and there is no residue or undissolved salt in the can when I am done mixing. Has saved me a lot of time when it comes to water changes. I usually only spend a 1/2 hour from start to finish on a 30 gallon water change these days.

[Hef]

I also follow the 5 minute system. Instead of buying that whimpy looking plastic mixer, I went to Home Depot and bought this wild looking Metal mixer. It churns the heck out of the water. I do about 7 gallons when I do it.
As far as the drill goes, I'm using a crappy Cordless Makita on High speed. I think any drill would be good enough, as they say in that article you want a high speed though. On low speed I get a nice whirlpool going but not like the High Speed.

hef

[G-money]

Mako,

Cool! Sounds like we mix the same size batches. I may have to try it on a smaller change for comparison-sake. Thanks for the link! BTW, I have a cordless drill that is only about 7-8 volts. Enough IYO? It has a 1/4" chuck.

[Hawkdl2]

I can't speak to others experience, but my corals do not retract for hours to days and my water doesn't not get cloudy. In fact there is no noticeable effect at all of adding mixed SW after a fairly short period of adequate mixing and aeration. Perhaps mixing in larger buckets with insuffiecient agitation results in pooer dissolution of the salts. This is not a problem for me in smaller (5 gal or so) batches.