Importance of TDS

[hjsvt]

Well this is months old but it's such a great article! And I want to bump it, so there!

A TDS meter is really cheap and is a staple in my testing box. I totally believe that TDS is much more important than pH to acclimation.

I completely agree on both parts. I now worry way more about TDS then pH. I test my TDS everytime I test my other parameters. I'm making my own RO water and I test it before i add anything to verify that my membrane is good and after I add my additives but before I add it to my tank. I want to make sure I haven't measured something incorrectly. I also replace all evaporation losses with straight RO water. IMHO a problem exists when regular water changes aren't done and evaporation is high and constantly replaced with tap water. Also interesting to note the last fish I purchased were in water with a TDS of 120. My tank runs about 375. I did a very slow drip acclimation for my shrimp and fish purchase and had zero losses. I didn't even measure the pH. Definitely agree more knowledge and discussion of this parameter would be great. Especially for beginners.

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[coralbandit]

Most informative!

I've read that a soft water fish can adapt to hard water relatively better, whereas hard water fish take longer as they are not used to pulling in whatever elements they need in softer water then they are used to. Does that make sense?

I'm wondering if certain fish will be more trouble-prone.?

Here's my take on this
Marine fish hold less "salt" in their system and intake what they need from the water.
The fresh water fish hold more"salt" in their system and release it as needed.
This(again as I understand) is osmoregulation.
So then it is my assumption that hard water fish don't hold up as well in soft water because the water lacks the minerals they need to uptake which leads to disease,and shorter life.
Where as the soft water fish already has too many minerals and only needs to expel them in hard water to stay in balance.
Anybody want to blow this up or say possibly?
Hey Jen!
I measure my TDS after I mix my water for my GBR breeding,and then for reference ,but still feel nitrates a better(more "accountable") way to track nutrients as opposed to "everything".

 

[Delapool]

Is a TDS meter really, really needed though? I test GH once in a blue moon as I figure 'meh, what am I going to do about it'.

Although I have to admit have been trying to swap to ferts I individually dose rather than pre-mixed ferts with high Mg since the last few tests.

Just adding that I use tap water (soft) for pwc though.

 

[Delapool]

Here's my take on this
Marine fish hold less "salt" in their system and intake what they need from the water.
The fresh water fish hold more"salt" in their system and release it as needed.
This(again as I understand) is osmoregulation.
So then it is my assumption that hard water fish don't hold up as well in soft water because the water lacks the minerals they need to uptake which leads to disease,and shorter life.
Where as the soft water fish already has too many minerals and only needs to expel them in hard water to stay in balance.
Anybody want to blow this up or say possibly?
Hey Jen!
I measure my TDS after I mix my water for my GBR breeding,and then for reference ,but still feel nitrates a better(more "accountable") way to track nutrients as opposed to "everything".

Sounds like a research project

My interest has been with mollies that I had read could swim between different SW and FW to aid getting rid of parasites, etc. Could be wrong, think it was just one article.

 

[sinibotia]

Sounds like a research project

My interest has been with mollies that I had read could swim between different SW and FW to aid getting rid of parasites, etc. Could be wrong, think it was just one article.

It may already have been researched...... if not? Brb, I have an application to submit to CUGR (center for undergraduate research) for the fall....

 

[coralbandit]

My only problem with TDS is it accounts for "everything".
Not every piece of driftwood in my GBR breeding tanks is the same size or even necessarily the same wood so when I measure my TDS after I install prepared water there are still too many variables to count it for much?
Using it as a gauge like gh/kh/ph is fine and I check all four in my water prep,but after when water is in tank the nitrate to TDS comparison did not hold up as a "even steven" rise.

Dela; part of the mollie changing waters and killing parasite is that different bacteria inhabit different waters and salt is known to irritate more then just the fishes skin! If you change a tank from fresh to brackish it is like cycling all over again as fw bacteria will die off and be replaced by the bacteria in a brackish/marine tank.
Sounds funny but as I understand they are different?

 

[Mebbid]

My only problem with TDS is it accounts for "everything".
Not every piece of driftwood in my GBR breeding tanks is the same size or even necessarily the same wood so when I measure my TDS after I install prepared water there are still too many variables to count it for much?
Using it as a gauge like gh/kh/ph is fine and I check all four in my water prep,but after when water is in tank the nitrate to TDS comparison did not hold up as a "even steven" rise.

Dela; part of the mollie changing waters and killing parasite is that different bacteria inhabit different waters and salt is known to irritate more then just the fishes skin! If you change a tank from fresh to brackish it is like cycling all over again as fw bacteria will die off and be replaced by the bacteria in a brackish/marine tank.
Sounds funny but as I understand they are different?

I actually used a freshwater filter in a salt water qt tank to test this. The interesting thing is that it was converting ammonia okay, but there was a backlog of nitrites.

I would imagine that the tds thing is less useful for an overall tank measurement, but instead is more important for acclimating fish to water. Following on threnjens statement, the tds is going to play a part in the regulatory function of the fish and a big shift can send them into shock.

If it was purely ph causing the shock, we would see massive fish deaths because of the large shifts in ph with pressurized co2.

 

[threnjen]

If it was purely ph causing the shock, we would see massive fish deaths because of the large shifts in ph with pressurized co2.

What is a common/accepted pH shift from day to night in a co2 tank?

 

[Mebbid]

What is a common/accepted pH shift from day to night in a co2 tank?

People dont really worry about the ph shift tbh, just the amount of co2. But it can be anywhere from 1 to 2 points. It can also happen really fast for people that use an air pump at night.

 

[Delapool]

What is a common/accepted pH shift from day to night in a co2 tank?

I was going to try and test that this weekend as I have a ph probe. I'd say it takes several hours to get the ph from say 7.5 to 6.9 using injected co2.

Normally it all shuts off but recently it ran out of co2 and I think it climbed back from 6.8 to 7.5 inside an hour. I had filters come back on. I need to record this properly though.

 

[Delapool]

I actually used a freshwater filter in a salt water qt tank to test this. The interesting thing is that it was converting ammonia okay, but there was a backlog of nitrites.

I would imagine that the tds thing is less useful for an overall tank measurement, but instead is more important for acclimating fish to water. Following on threnjens statement, the tds is going to play a part in the regulatory function of the fish and a big shift can send them into shock.

If it was purely ph causing the shock, we would see massive fish deaths because of the large shifts in ph with pressurized co2.

Yes, I never see any issues. However I think that if you are changing ph using buffers then the ph reading is a proxy for what kh and TDS are doing. In that case I think ph changes should be more gradual as suggested by product guidelines. Or is that rubbish?

 

[Delapool]

My only problem with TDS is it accounts for "everything".
Not every piece of driftwood in my GBR breeding tanks is the same size or even necessarily the same wood so when I measure my TDS after I install prepared water there are still too many variables to count it for much?
Using it as a gauge like gh/kh/ph is fine and I check all four in my water prep,but after when water is in tank the nitrate to TDS comparison did not hold up as a "even steven" rise.

Dela; part of the mollie changing waters and killing parasite is that different bacteria inhabit different waters and salt is known to irritate more then just the fishes skin! If you change a tank from fresh to brackish it is like cycling all over again as fw bacteria will die off and be replaced by the bacteria in a brackish/marine tank.
Sounds funny but as I understand they are different?

Perhaps it would be into salt baths at this point rather than tank dosing? Reading I've done suggests this is more effective for parasites than bacteria but I've wondered if a salt bath for live bearers would be just as effective as antibiotics.

Partly because salt is pretty common in the house so early treatment, also any small fish with a bacterial infection is a tough cure anyways and also because here in Australia we are stuck with tetracycline and triple sulpha unless others are ordered in and kept in stock (which is expensive for something you hope not to use).

Thoughts?

 

[Caliban07]

Here's my take on this
Marine fish hold less "salt" in their system and intake what they need from the water.
The fresh water fish hold more"salt" in their system and release it as needed.
This(again as I understand) is osmoregulation.
So then it is my assumption that hard water fish don't hold up as well in soft water because the water lacks the minerals they need to uptake which leads to disease,and shorter life.
Where as the soft water fish already has too many minerals and only needs to expel them in hard water to stay in balance.
Anybody want to blow this up or say possibly?
Hey Jen!
I measure my TDS after I mix my water for my GBR breeding,and then for reference ,but still feel nitrates a better(more "accountable") way to track nutrients as opposed to "everything".

It's not that marine fish hold 'less' salt it's because the environment around them has such a greater salinity. Water wants to be expelled from the fish to equalise the concentration of salts internal and external to the fish. This isn't something that is going to happen but it osmosis is something that the fish has no say over. Marine fish are in danger of dehydration because of their constant loss of water to the environment in order to prevent dehydration they have to continuously 'drink' water to replace fluids and maintain a certain salinity in their bodies that has constantly being lost.

I would actually agree and say that hard water fresh water fish will have more of a difficult time acclimating to softer water as they will have to continuously expel more water that wants to enter their bodies. This could overwork the kidneys because of the dilute urine being created and expelled. And the system and Gill cells will have to work harder to take up salts that have been lost.

Once the fish is happy with the new demand and is being fed well enough to keep up with it things should be ok. But constant large fluctuation will force the body to adapt. Even if the fish is placed back in to hard water it takes energy to regulate back.

if you change enough water and maintain 50% weekly on the same routine. Using a TDS meter you can actually see the TDS level Peter out to a certain point ( it will not go any lower unless you change more than 50%) this level is you baseline where fluctuations are less likely when adding in new tap water. 50% keeps the water clean and the parameters stable as TDS is all dissolved solutes that can pass through a 2 micron filter that means everything is kept in check including nitrates.

Monitoring TDS can enable you to see how much things are changing week by week and see how effective or ineffective your water changes are becoming over time. It makes sense to constantly check tap water TDS too.

I'm not saying a large fluctuation is going to kill fish but rather that they will not readily appreciate it. Fish like stability another change means another major re-acclimation which means more work. If the fishes immune system is already compromised this isn't going to help.

I believe salt baths to be a double edged sword. Whilst Increased salinity levels may help to fight infection I don't see how an already weakened fish can benefit.


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[sinibotia]

Just a fun fact about all of this: Sharks and other elasmobrachs are actually unique in that they osmoregulate more like freshwater fish- they actually have more salt in their blood than is in the seawater and are thus constantly working to retain salt. (And 60% of the contents of their blood is urea).

 

[ImACoolguy]

Some gave me the back to the future car and I went back to biology class for this read. don't think I have grasped the whole concept in depth but merely a basic understanding that TDS is important and how to manage it.

Some of that definitely went above my head though


Caleb

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[coralbandit]

I dropped my TDS meter in water today!
It is not water proof!
I don't use it to test my tanks water but to properly prep water!
Ordered two new ones today!
One is water proof and the other I will put back on my ro unit!
Both HM digital Units.

This was like losing electricity to me as I would be mixing/remineralsing my water by mere math and measuring spoons!
I can manage for a couple days but for me I need to have a TDS meter almost everyday(I change and mix a lot o water!).

 

[Brookster123]

Tds question!! Checked mine today in all the newly set up tanks. Reading 300-400 which is tooo high.. checked the source and it's 120. Think all the stirred up new substrate and such could be messing with readings? free floating particulates??

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[Brookster123]

I dropped my TDS meter in water today!
It is not water proof!
I don't use it to test my tanks water but to properly prep water!
Ordered two new ones today!
One is water proof and the other I will put back on my ro unit!
Both HM digital Units.

This was like losing electricity to me as I would be mixing/remineralsing my water by mere math and measuring spoons!
I can manage for a couple days but for me I need to have a TDS meter almost everyday(I change and mix a lot o water!).

Amazon prime that baby!!!

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[coralbandit]

Tds question!! Checked mine today in all the newly set up tanks. Reading 300-400 which is tooo high.. checked the source and it's 120. Think all the stirred up new substrate and such could be messing with readings? free floating particulates??

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Ya the difficulty with TDS in the tank is you really don't know what you are reading..
You are measuring EVERYTHING!!
I would think it is the play sand...
My tap is 370!!
Same water I sell my rams from!(not breed)

Amazon prime that baby!!!

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I have to have it or could I blow up!
My rams are my main focus for years now so to go a day without necessities is stressful for me.
We all know stress is not good.
ordered mine from BRS as I needed to get more DI resin and filters for my ro anyways!

 

[Brookster123]

Ya the difficulty with TDS in the tank is you really don't know what you are reading..
You are measuring EVERYTHING!!
I would think it is the play sand...
My tap is 370!!
Same water I sell my rams from!(not breed)



I have to have it or could I blow up!
My rams are my main focus for years now so to go a day without necessities is stressful for me.
We all know stress is not good.
ordered mine from BRS as I needed to get more DI resin and filters for my ro anyways!

Didn't even check the new 75. It was the other 4 tanks..

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