Removing chlorine with aeration to keep TDS lower?

Is it worthwhile to let city tap water treated to .5ppm chlorine levels (not chloramine) sit out with aeration rather than using prime or safe in order to keep TDS lower? I imagine the dechlorinator adds some additional dissolved solids that Rams don’t need? If I let the water age with aeration, how long does it have to sit before using it to do a water change? Letting the water age is also beneficial because the Ph drops from 9 to 7.5 in 24 hours. Since I want to let it age anyway, why not skip the dechlorinator?

 

The extra TDS doesn’t really make any difference but you save money on dechlorinator so it’s a win as long as you don’t mind the wait and have a place to keep the water.
I don’t know how long you would need to aerate, perhaps overnight to be safe if you can’t test it but another method is to leave a bucket of water in the sun; on a clear summer day it takes about 1-2 hours for the UV rays to dechlorinate a 5 gallon bucket.

 

o keep TDS lower? I imagine the dechlorinator adds some additional dissolved solids that Rams don’t need?

Ideally you would use RO, which doesn't require any de-chlorinator. Your thought is technically right, but only relevant if you have your tank at TDS significantly below 50mg/l in clear- or blackwater conditions. The TDS added by de-chlorinator in a tank run with tap are negligible.

 

Ideally you would use RO, which doesn't require any de-chlorinator. Your thought is technically right, but only relevant if you have your tank at TDS significantly below 50mg/l in clear- or blackwater conditions. The TDS added by de-chlorinator in a tank run with tap are negligible.

My tap water is 83 TDS so I am trying to limit adding anything extra to keep it close to 100 with plant ferts, dechlor, waste etc.

I have heard in order to breed the Rams to keep TDS at 100. Mid week I am at 115 TDS. I can cut it with a little RO or rainwater if necessary but I haven’t been doing that with my Rams yet because they seem happy and are spawning. It’s a clearwater tank with driftwood.

 

Your tap water has a really awkward reading. Do you know what the 83 are comprised of? Nitrates? GH? KH? Anything else?

I have heard in order to breed the Rams to keep TDS at 100. Mid week I am at 115 TDS. I can cut it with a little RO or rainwater if necessary but I haven’t been doing that with my Rams yet because they seem happy and are spawning. It’s a clearwater tank with driftwood.

I'd go the full mile and go lower. Slowly of course, but it would be possible for you to go below 100 easily. I would not stop at 100. Below that would be beneficial for the viability of the spawn.

 

Your tap water has a really awkward reading. Do you know what the 83 are comprised of? Nitrates? GH? KH? Anything else?

Zero nitrates. 35.8 ppm KH and 71.6 ppm GH when I tested that a long time ago. Somebody also told me that they put some kind of chemicals in the water to raise the pH so they don’t leach lead out of the pipes. That allegedly offgases within 24 hours which is why the pH drops. I haven’t tested the TDS immediately out of the tap and again 24 hours later in aged water but that would be interesting.

 

Well, then. I'd be testing right now in your place.

 

Well, then. I'd be testing right now in your place.

I tested tap water vs water aged 24 hours in a bucket and they both read 90-91 yesterday. I was surprised that there was no difference. I guess I don’t know enough about the chemistry whether a dissolved gas in water would read it as a dissolved solid? I guess not. Maybe the chemical that is dissolved in the water to protect the pipes is a gas. The guy said that it will off gas within a day.

 

Aging water does not change the TDS. When you age water with an air stone it stabilizes the pH. It is the constant swing in pH that bothers sensitive fish like Rams and Discus. 90 TDS should be fine for breeding in most cases. Just keep the pH stable and your fish will be happy. I breed both Rams and Discus. A swing of under .2 is not a problem for them. If the swing is more you should age. I do. It's really no big deal. All that's needed is an air stone and a heater to match the temp of your tanks. My swing is from 6.8 to 7.2 so I age my water. I age mine for 24 hrs because Discus like their water changed every day. Rams are less picky and can go for a few days as long as their tank is clean.

 

I tested tap water vs water aged 24 hours in a bucket and they both read 90-91 yesterday. I was surprised that there was no difference. I guess I don’t know enough about the chemistry whether a dissolved gas in water would read it as a dissolved solid? I guess not. Maybe the chemical that is dissolved in the water to protect the pipes is a gas. The guy said that it will off gas within a day.

Erm... I thought you would compare the pH, not the TDS. Those for sure wouldn't change.

My swing is from 6.8 to 7.2 so I age my water.

0.4 is still not much of an amplitude. Nothing to bother about, especially if it's in the neutral zone.

 

MacZ - Oh, I have already tested the pH out of the tap (8.6) and 24 hours later (7.2). Gary Lange of rainbowfish fame told me the water company probably puts sodium hydroxide in the water to reduce lead leaching, and it offgasses causing the pH to drop to neutral.

 

Soda Ash or Sodium Hydroxide will raise pH from Acid to neutral 7, but it won't run it up to 8.6. Sodium Hydroxide will raise pH. I suppose free soudium and hydroxide ions will bind with CO2 in the water and neutralize carbonic acid created.......

Due to Henry's Law, ( look into it! ), As the water sits, it absorbs and released CO2 to balance out with the atmosphere above the water. This creates carbonic acids that should lower the pH. totally normal process with atmospheric difference between atmosphere and water, and contained water that is delivered by container or pipe that hasn't adjusted and remains as it was until given atmosphere.

As far as why it's coming out at 8.6, well they are treating the water I suppose, and it seems like they are pulling something with it to get it up to 8.6 pH for pipe delivery and kicking down GH and KH.....
I "think", (and it's a guess) but your source water before water treatment is high pH and probably highly alkaline as to why it's high pH, and they are treating it down with acids. so it doesn't cause corrosion through calcium and magnesium buildups inside the pipes ( Sodium carbonate or Bicarbonate would . when it's allowed to sit after drawing it, it's taking acids from CO2 from the atmosphere, and that's dropping the pH even lower. 9+ alkaline will cause deposit buildups that will cause corrosion of pipes.

I "think" they are degrading The GH and KH with acid injection to actually lower the pH from the source for the delivery through the pipes. hydrosulfuric acid = hydrogen Sulfide maybe this degrading CO2 that Henry's Law says will enter the water, consumes more buffer, as it lowers pH further from sitting as it balances.

Sodium Hydroxide will generally raise KH, I don't think that's what they are doing with KH right about 2 dKH.