Using Cold RO/DI Water When Mixing Salt

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10gnano

Well-known member
Joined
May 30, 2010
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198
Location
seattle, wa
Does using cold RO/DI water change the chemistry of the saltwater while it's mixing? I've never used a heater when mixing my saltwater. I've been mixing about 3-4 gallons at a time, this reduces the tank water by a .5 degrees when I add it in my tank. Is this supper stressful for my corals? I know this maybe a newbie question.

I'm stumped my corals are not coloring up to full potential and it is really starting to bug me. I'm going to pick up another pump to get more flow, but I'm trying to think outside the box on what is going on here.
 
Corals not coloring up is not due to flow issues it's due to a high nutrient problem and poor lighting is a cause for some dull or brown outs
 
The pump is just for extra flow in the tank. Not sure why I put that in, just thinking about other stuff that I needed to do to the setup as I was writing this.

Nothing is browned out it looks as if they are bleached. Params seem to be in check and my lighting should be fine. I have the AI sol blue. Corals are growing/encrusting so i'm thrown on this one.

The main questions is that by using cold water while mixing my saltwater is this having any effect on the water chemistry?
 
You should mix and match your water parameters exactly to what your DP water including temperature. The mix will dissolve easier when the water is warmer as compared to really cold water this time of year, sometimes a small PH in the bucket with such small amounts running overnight would warm it up enough but you need to test your water regardless. You will notice a difference right away when you do it properly and sometimes you actually should do a large wc if your having nutrient issues.
 
You should mix and match your water parameters exactly to what your DP water including temperature.

Exactly.

The mix will dissolve easier when the water is warmer as compared to really cold water this time of year
With all due respect unless you're talking about near freezing water temps this isn't the case IIRC. The salt actually mixes better at less than "Reef" temps and many chemically inclined reefers highly suggest not heating the water until after the salt mix is added to the batch. Depending on how you're testing your water (Temp Adjusted etc) you will probably want to get it up to Tank Temp before testing.
 
With all due respect unless you're talking about near freezing water temps this isn't the case IIRC. The salt actually mixes better at less than "Reef" temps and many chemically inclined reefers highly suggest not heating the water until after the salt mix is added to the batch. Depending on how you're testing your water (Temp Adjusted etc) you will probably want to get it up to Tank Temp before testing.

Well that is what I said, with cold water this time of year, meaning really cold water.
 
I have my mixing tubs in an unheated basement. I usually turn on the heater/powerhead (20 gal) and then add salt and wait 24-48H.

I was wondering the same though, as the new water usually has a 'hint' of cloudyness that disappears within a half hour of adding to the DT (~20% water change.)

With the slight cloudyness, I was wondering if some of the Ca was precipitating. I tried heating it first this time this water change (will add to tank this evening.)

But, good to know about mixing cold then heating before adding to tank.
 
Well that is what I said, with cold water this time of year, meaning really cold water.
I hope I didn't offend you. It's probably different there but our water here never gets below about 45 degrees even with a long cold deep freeze so I've never had to deal with water at or near 32 degrees.
 
I've always added ambient temperature water to my tank when doing water changes. In my case, that's generally 10 gallons of water in a system that's probably 220-230 gallons total so it doesn't make a huge difference in temperature. In your case, I'd drain off what I wanted to replace and then add the fresh saltwater back in small portions until the exchange is complete. 3-4 gallons being introduced to the tank over the course of an hour or so would have very little effect on water temp.

As far as your corals are concerned, I don't think your water change regimen is causing them to not color up. Assuming that you're using a quality salt, mixed to 1.026/35ppm (or thereabouts), and your water parameters are in line for temp, pH, Alkalinity, Phosphates, and Nitrates then I think you need to look at lighting or placement in the tank. If you think flow is the issue, as in not having enough to keep the coral clean and happy, try using a turkey baster several times a day to remove sediment from your corals. If you notice a positive response to this then look at adding a powerhead setup in the tank. I have a Reeflo Barracuda, 3 Tunze 6105s, and an Ecotech MP40W and still use a turkey baster to "wash" my corals periodically.

Do us a favor and post up all your water parameters.

Mike
 
I hope I didn't offend you. It's probably different there but our water here never gets below about 45 degrees even with a long cold deep freeze so I've never had to deal with water at or near 32 degrees.

Even down south like where I'm at we get very cold water from time to time, that is what was said so I assumed it was really cold. I like to mix it at or around room temp but you can mix it colder, I just find it seems to mix better, and then let the ph slowly heat it as you let it mix overnight. Now that said mixing it at this cold temp. shouldn't effect the chemical makeup of the salt, which was the original question, once it is warmed up to tank temp. the parms. should be tested.
 
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