High TDS

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

earhtmother

Aquarium Advice FINatic
Joined
Mar 22, 2010
Messages
975
I have a 70g which had an 18" Knife in it until 3 mths ago when plans to upgrade his tank fell through & I rehomed him. I cleaned the gravel & left both filters running and was using it to hold duckweed for lack of a direction in which to move fish wise. I think I was going to move the Oscar in here for now from the 55g until I can afford another 90+ but when I tested the TDS which is generally all I keep track of it was sitting at 800 [emoji44] All my tanks run high since my tap water is around 350 but the fish & neo shrimp are doing fine. Why is this one SO high, I am assuming lack of fish inhabitants/food (still has MTS) so I just wanted to make sure grumpy wasn't going to do more than sulk if he got moved.
 
I have a 70g which had an 18" Knife in it until 3 mths ago when plans to upgrade his tank fell through & I rehomed him. I cleaned the gravel & left both filters running and was using it to hold duckweed for lack of a direction in which to move fish wise. I think I was going to move the Oscar in here for now from the 55g until I can afford another 90+ but when I tested the TDS which is generally all I keep track of it was sitting at 800 [emoji44] All my tanks run high since my tap water is around 350 but the fish & neo shrimp are doing fine. Why is this one SO high, I am assuming lack of fish inhabitants/food (still has MTS) so I just wanted to make sure grumpy wasn't going to do more than sulk if he got moved.
Well I am surprised how your neos are alive. I know they are hardy but 800 is extremely high for fish or invertebrates. If your tap water is 350 then why it shows 800? Did you check your tds meter if its fine? Please check in distilled or ro water to see if it is working fine. If i were you i would slowly reduce the tds. So sudden change will give your fish and invertebrates a big shock. Shrimps are more ok from goinh from low tds to high but when you move them from high to low thats gonna be very stressful. Please try to find out what is causing this high tds. Something maybe leaching in water? You add something in water like fertilizers or something or any thing to buffer?
 
Do you have a planted tank? Fertilizers raise TDS. Do you have a hot water heater in your home and do you use your warmed tap water to do water changes?

You may have to mix 50/50 tap with R/O.
 
Just filling with tap water over and over and over and over increases TDS. Solids stay in the water while the water evaporates.

Kashif314 is right about sudden change of water parameters.

You can easily start doing pwc every day. Smaller to start, like 10-15% daily for few days, then maybe 15-20% a week, then 25% daily for a week and then check the numbers again, and then slightly larger pwc few times over a week, check again. So that you can get the tank water closer to the tap water TDS.

One issue about testing TDS is you do not know what all the TDS is comprised of.

Try testing GH and KH for tank and then tap - compare, and see how far apart you are. Other contents may be organics creating a high TDS.
 
Don't test TDS too soon after fertilizing or doing other stuff into the tank, wait 12 hours. Also I seem to remember that testing even after using Prime will indicate elevated numbers.
 
If you have a hot water heater that's fairly old it will have a build up of solids in it which will raise your TDS as high as 150-200 ppm just by using any amount of hot water. If this is the case you may have to use cold water and heat it with a heater before adding it to your tank for a water change.
 
I use water from my water heater and it does not raise my TDS a bit .
As a mater of fact the crystallization that takes place in the heater actually removes a little of the TDS. Think about it ;The heating element gathers the minerals on it, it does not produce them...Just like my old distiller the crap left behind in the hot water tank is a lot of the dissolved minerals.Maybe at some point they may come out but I have not experienced this in years of mixing warm and cold water.
I agree to change more water or maybe even use ro.

What substrate are using? Some of them release minerals into the water column......
 
Case and point......recently tested my dad's TDS with straight up cold water out of the tap. TDS was 180 ppm. Tested the water at 84 degrees immediately afterwards and TDS was 365 ppm. Tested cold again immediately after this and TDS was 180 ppm again. Tested the cold water out of the faucet outside the house and it was 180 ppm. His hot water heater is 20 years old. DS is salts and minerals. Most hot water heaters will get a build up of these two things in them over time and go out. Especially if your area has harder water. If you don't believe it, the next time your old hot water heater goes out tear it open and look in the bottom before you throw it away. I'd think if water is passing through these solids that have built up in a hot water heater before it comes out of your tap it will raise the TDS. If this isn't the case then I have absolutely no idea why the TDS at my father's house is doubling out of the same water line between the cold and hot water.

I tested this on my own house as well. I have a 10 year old hot water heater. The TDS out of the tap on cold is 179 ppm. At 84 degrees it is 220 ppm. Not quite as much of a jump but probably not as much dissolved solids built up in my tank yet. I tested the cold water out of my faucet outside and it was also 179 ppm. Every time I tested I did 3 tests to see if anything changed and it didn't.

Might be worth taking your TDS meter and testing this for yourself.
 
Also scrutinize any rocks you may have in your tank. Many types of rock can fiddle with your pH and hardness.
 
I'll preface this by stating it has taken me 3 attempts to write this as the first few responses I wrote were as judgemental as some of your responses. What is most annoying is that my actual question was never addressed, most of you simply just saw the high TDS numbers and proceeded jumped all over me.*

I asked what was causing a high TDS reading in this particular tank as the only difference between it and my other 5 was it's current lack of fishy inhabitants.* I am still assuming it was due to this and the mess that Henkel the knife left it in* as he was as temperamental as any oscar when it came to fussing in his tank so the maintenance was minmal to avoid disturbing him. I have now vacuumed the gravel 3 times which of course means a 60/75% WC when doing it with a Python and my TDS is now in the high*300s*so the oscar will be moving in this*afternoon much to his annoyance at the *up close*personal*attention*


Kashif314

I NEVER said I was keeping ANYTHING in this tank right now or that ALL my tanks had an 800 TDS reading, why you thought this I am not sure.*


Autumnsky

I don't know why YOU assumed I was only doing top offs as I never mentioned my WC routine at all. FYI I do a weekly 50% WC on all my tanks (except the shrimps who get around 25 or less)


Everyone*

My tanks have been up & running almost 10 years at this particular location and other than the usual losses to diseases, equipment failure and unexpected environmental occurrences (heatwaves or cold snaps) the fish are doing fine and the shrimp are comfortable* enough to repopulate their tank so I am not worried that the TDS is running as high as it usually*does, when it increases I look for the reason but if it stays in its usual range I leave it be.
 
I'll preface this by stating it has taken me 3 attempts to write this as the first few responses I wrote were as judgemental as some of your responses. What is most annoying is that my actual question was never addressed, most of you simply just saw the high TDS numbers and proceeded jumped all over me.*

I asked what was causing a high TDS reading in this particular tank as the only difference between it and my other 5 was it's current lack of fishy inhabitants.* I am still assuming it was due to this and the mess that Henkel the knife left it in* as he was as temperamental as any oscar when it came to fussing in his tank so the maintenance was minmal to avoid disturbing him. I have now vacuumed the gravel 3 times which of course means a 60/75% WC when doing it with a Python and my TDS is now in the high*300s*so the oscar will be moving in this*afternoon much to his annoyance at the *up close*personal*attention*


Kashif314

I NEVER said I was keeping ANYTHING in this tank right now or that ALL my tanks had an 800 TDS reading, why you thought this I am not sure.*


Autumnsky

I don't know why YOU assumed I was only doing top offs as I never mentioned my WC routine at all. FYI I do a weekly 50% WC on all my tanks (except the shrimps who get around 25 or less)


Everyone*

My tanks have been up & running almost 10 years at this particular location and other than the usual losses to diseases, equipment failure and unexpected environmental occurrences (heatwaves or cold snaps) the fish are doing fine and the shrimp are comfortable* enough to repopulate their tank so I am not worried that the TDS is running as high as it usually*does, when it increases I look for the reason but if it stays in its usual range I leave it be.
No one jumped over you or said you did anything wrong. We are not present at your place so how can we say you what is causing the high tds without asking the basic questions like if you have any routine to add any fertilizers or something or some other questions which were asked to determine what the issue might be.

If you want a short answer then NO only fish waste or left over food can't cause tds to jump to 800 even if you do partial water changes after two weeks. Tds will go to 800 if a tank is unattended for months.
 
No YOU assumed I was keeping fish & shrimp in it which I never said and as I had NOTHING in the tank I was simply asking what was causing the high reading while pretty much everyone assumed ALL my tanks were ridiculously high. I said there was nothing in the tank in original post and yet nobody seems to have read or even reread to verify what I actually said before saying anything. Obviously it WAS food waste in an unoccupied tank that caused the rise because there was nothing else except a low temp & running filters & MTS in the tank
 
No YOU assumed I was keeping fish & shrimp in it which I never said and as I had NOTHING in the tank I was simply asking what was causing the high reading while pretty much everyone assumed ALL my tanks were ridiculously high. I said there was nothing in the tank in original post and yet nobody seems to have read or even reread to verify what I actually said before saying anything. Obviously it WAS food waste in an unoccupied tank that caused the rise because there was nothing else except a low temp & running filters & MTS in the tank
I misunderstood. English is not my native language. I re read your post. Sorry for the misunderstanding. I thought neos in your 800 tds tank. Now i re read and its in 300+ tds tank which is perfectly ok for neos. I just don't understand something dear why you getting hyper over it? Ok i misunderstood but others did try to help you sincerely. As I said only fish waste or food can't make a 300 tds to 800 but if your fish is doing fine then its ok I guess or you can reduce it gradually whenever you see its creeping. Again sorry for misunderstanding.
 
Why is this one SO high,
Your quote from the original post.....

What is most annoying is that my actual question was never addressed, most of you simply just saw the high TDS numbers and proceeded jumped all over me.*

*****[Many comments were about HOW TDS can get that high, not that you were doing or not doing anything personally, but also how to possibly correct it.]

Autumnsky

I don't know why YOU assumed I was only doing top offs as I never mentioned my WC routine at all. FYI I do a weekly 50% WC on all my tanks (except the shrimps who get around 25 or less)

*******[I never assumed anything about how you run your tanks, but only mentioned one and then other, of the most common ways that tanks end up with very HIGH TDS ( and how to solve it by gradual water changing (in case you DID have any fish in there) and also chemical and resin based additives to help reduce it, and vac'ing substrate, all ways to help fix the problem.

Never intended the comment to imply in any way how you keep your tanks, I would never be able to remember all details of each members tank keeping comments/posts through out the months and years of hanging out with all of you.

So sorry if it felt as though you were being attacked or jumped on about it. Not my intention, just throwing out ideas on what could have caused it.

Plus the part I read and noticed is the highlighted blue part in the OP, which I thought I was helping with]

I will be bowing out of the future / continued posts for this thread. Please feel free to PM me if there is anything I can help with. Hoping that the problem you have will get good answers for a quick solution.
 
"Obviously it WAS food waste in an unoccupied tank that caused the rise because there was nothing else except a low temp & running filters & MTS in the tank"

Based off this comment I'm not sure why you asked for advice on why your TDS was high if it was obvious to you? Then got mad because others didn't know what you already knew?.....
 
Did you ever consistently check the TDS when the knife fish was in the tank? What did you feed him?

I raised my TDS by 100 just by feeding copepods. They were in salt water. Didn’t even realise.

An 18 inch fish and snails would be enough to raise TDS significantly I’d imagine.

One things for sure though. I take most things I read about aquariums with a pinch of salt these days. Literally every recommendation that comes about I’ve seen people doing the exact opposite with no issues.

I guy I know nearly caused mass hysteria when he presented his Rotala Wallichii growing perfectly healthy in 800+ppm water. It was growing healthier than those actively trying to tailor to its needs haha.
 
"Obviously it WAS food waste in an unoccupied tank that caused the rise because there was nothing else except a low temp & running filters & MTS in the tank"

Based off this comment I'm not sure why you asked for advice on why your TDS was high if it was obvious to you? Then got mad because others didn't know what you already knew?.....
It *wasn't* obvious to me until nobody could give me any other explanation. The tank always read the same as my other tanks while the knife lived there, high but not *that* high. Since nobody could offer any other explanation other than the usual (dosing new decor etc) then the only thing left was the fact that it had been *running* with no actual inhabitants other than the MTS which I am assuming have a very small bio footprint
 
Dear earthmother my question is why you got hyper over it? Please do yourself a favor and ask (copy paste) this very same question in some other fish forum and share screenshots of replies you get. I am 200 percent sure you ll get similar replies like what we gave you. As I said we are not present at your place so we need to know few things before we can rule out the problem and we are just hobbyists. Some are very expert but some are like me. But we do try to help as we can.

Again no one jumped at you. Asking questions is not jumping on you. It was to rule out the problem. Please take it easy
 
Back
Top Bottom