# Using a TDS meter for nitrate checks



## MEDHBSI

So i was wondering if anyone else uses a TDS meter to do a quick check on there nitrate lvl's. I've been doing this for a while now and it really seems like an easy way to check on the nitrates without using drops. I check my tap water it reads 14 TDS, then i check my aquarium it should be around 22 TDS so when it gets to about 40 TDS i change my drip filters. I also do check my nitrates periodically just because im always worried


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## Bobsidd

Could the TDS reading not be made up of other dissolved substances than nitrate? I'm not sure that they equate. But if they do I'd be very happy to throw away my ten drops-shake-shake for 30 seconds-10 drops-shake for a minute-wait for five minutes pain in the neck test kick and vote for you as prime minister. I hate testing for nitrates.


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## MEDHBSI

Bobsidd said:


> Could the TDS reading not be made up of other dissolved substances than nitrate? I'm not sure that they equate. But if they do I'd be very happy to throw away my ten drops-shake-shake for 30 seconds-10 drops-shake for a minute-wait for five minutes pain in the neck test kick and vote for you as prime minister. I hate testing for nitrates.


Yes i suppose other things could cause tds's but I've been checking for months and doing random drop tests with no issues


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## Bobsidd

It probably is a very good indicator. Especially if most other things in your tank remain pretty constant.


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## charles

40PPM is very low. Fish do need some dissolved minerals in the water. In general, for SA biotope, my tank is between 80-100ppm. Your GH and KH must be 0. 

You can use TDS to guessimate. But nothing beat a good nitrate test kit. If you want to skip the testing, do it this way. Assuming you are not adding any fish. When you tank is stabled, do a nitrate test before you do a water change. Then do your water change and test your nitrate again an hour later. It should be much lower than before. Now continue with your regular feeding, but skip your routine water change. Get a nitrate reading every 3 days. Record how many days your nitrate reaches your unacceptable level, then do a water change. However how many days it takes the nitrate to get up, that is normally the number of days you can go without your water change.

Don't apply this when you are trying to grow discus.

You can use your TDS along the way while doing your nitrate test method above. Do a TDS reading before your water change. Then continue to record your TDS reading till the day your nitrate is too high, your TDS reading should increase. Record that you can do quick TDS reading in between the period and monitor your tank in case you are overfeeding, overdoing, or adding new fish.

I hope this help.


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## charles

remember any added mineral or dosing will increase your TDS reading... I would just use it as a quick lazy reference. But I would not rely on it as a substitute of a nitrate test.


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## MEDHBSI

charles said:


> remember any added mineral or dosing will increase your TDS reading... I would just use it as a quick lazy reference. But I would not rely on it as a substitute of a nitrate test.


I use a drip system my tank has been stable for a very long time  water changes are for suckers  I've never had an issue with a tds of 20ppm my tap water goes as low as 5


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## smccleme

Drip is the way to go (especially if you have sump). When I first added my auto change system I was constantly measuring nitrates and adjusting the drip (it was actually a stream) rate in an effort to keep nitrates below 20ppm. Eventually I concluded that that was a waste of water. Since then, I've slowed the drip and the nitrates stay around 40ppm. The water is crystal clear and the cichlids bread constantly. With the drip, the nitrates will only rise so far - as they increase the difference between the fresh water and changed water grows to the point where it stabilizes. I believe this is healthier for the fish - constant PH and nitrate levels, versus the swings experienced with large water changes.


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## charles

in my experience, a swing of nitrate will not affect the fish. It is like saying poor air quality in the room, and replace that with 50% good fresh air for human. my acceptable level of nitrate is 20ppm. And that is what most people do as well. 40ppm in my opinion is high. But that is just me.

Ph swing, I agree. We have to keep that consistant.


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## Fish rookie

This is a very informative thread, thanks everyone for the input. I have been thinking about setting up a drip /automatic system but I cannot get over the fact that with a drip system the water is never really clean, is it? With a 100% water change I can bring the pollutant down to zero or very close to zero and when it gets a bit dirtier (e.g. nitrate =10ppm) or in my case even less (I do 2 water changes of 100% a day) I do another 100% water change. But with a drip the pollutant is just constantly being diluted yet present so the fish are constantly being subjected to them. Or am I missing something here? 
About TDS, my TDS out of my tap is about 6 with gH=kH=0, I increase my hardness to about 70-100 with the additional of calcium chloride, magnesium sulphate and some phosphate and potassium after each water change. I am talking about my discus grow out tank. I do not think they mind any swing during each water change. I feel, but it is just my humble opinion, they actually enjoy the fact that the water is being changed often. They appear more lively and lighter in color during and after each water change. They even feed during water change. They would mind if I do not change their water. It may be just because they are used to the quality of the water being very low in dissolved organic? I think the dissolved organic level in a drip system will definitely be higher, unless the drip rate is very fast. 
I think using TDS as an indication is workable especially if you have a set routine of how much you feed and the number of fish are set and they are grown so not much will change from day to day. 
In the future, if I have lots of tank I can see that changing a lot of water frequently will not be practical hence my looking into an automatic system. I am at this point more inclined towards something that can change at least half of the water at a time in an automatic manner. I am not too sure about a drip. May be it is more suitable for other fish but not discus? I am not sure.
In most cases, is a drip system more like a way to delay water change or an attempt to eliminate it completely? I can see that being a way to delay water change and reduce the frequency of it, but I just cannot understand if it is used to eliminate water change completely how the water can be "cleaner" than manually doing big frequent water changes.
I would love to hear what you guys think, if you dont mind. Thanks a lot.


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## smccleme

I use both methods; continuous drip on the 155g, and semi-manual changes on the 125g. 

To make water changes easier, I have a permanent line hooked over the 125g running to the laundry room sink. I open the valves and it drains out 30% of the water. I then refill the tank with the line using a timer that fills it almost all the way. I then manual watch it top the tank off and shut the line off. The water change takes a couple hours to do (it's a 3/8ths line, so it takes over an hour to drain the tank), but only requires my attention for 5 mins.

Even though the manual change doesn't take a lot of time, I still prefer the auto system and will eventually add it to the 125g as well.

Both tanks have happy, healthy cichlids.


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## MEDHBSI

I've got 13 healthy and fat discus in my 230g I drip 3 gallons per hour with 2 stingrays in there as well my TDS stays at 21 but if i was to drip more it would go down to about 13



Fish rookie said:


> This is a very informative thread, thanks everyone for the input. I have been thinking about setting up a drip /automatic system but I cannot get over the fact that with a drip system the water is never really clean, is it? With a 100% water change I can bring the pollutant down to zero or very close to zero and when it gets a bit dirtier (e.g. nitrate =10ppm) or in my case even less (I do 2 water changes of 100% a day) I do another 100% water change. But with a drip the pollutant is just constantly being diluted yet present so the fish are constantly being subjected to them. Or am I missing something here?
> About TDS, my TDS out of my tap is about 6 with gH=kH=0, I increase my hardness to about 70-100 with the additional of calcium chloride, magnesium sulphate and some phosphate and potassium after each water change. I am talking about my discus grow out tank. I do not think they mind any swing during each water change. I feel, but it is just my humble opinion, they actually enjoy the fact that the water is being changed often. They appear more lively and lighter in color during and after each water change. They even feed during water change. They would mind if I do not change their water. It may be just because they are used to the quality of the water being very low in dissolved organic? I think the dissolved organic level in a drip system will definitely be higher, unless the drip rate is very fast.
> I think using TDS as an indication is workable especially if you have a set routine of how much you feed and the number of fish are set and they are grown so not much will change from day to day.
> In the future, if I have lots of tank I can see that changing a lot of water frequently will not be practical hence my looking into an automatic system. I am at this point more inclined towards something that can change at least half of the water at a time in an automatic manner. I am not too sure about a drip. May be it is more suitable for other fish but not discus? I am not sure.
> In most cases, is a drip system more like a way to delay water change or an attempt to eliminate it completely? I can see that being a way to delay water change and reduce the frequency of it, but I just cannot understand if it is used to eliminate water change completely how the water can be "cleaner" than manually doing big frequent water changes.
> I would love to hear what you guys think, if you dont mind. Thanks a lot.


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## Fish rookie

21 is very low...is it a barebottom tank?


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## MEDHBSI

Yes its a bare bottom tank but with 13 large discus, 2 stingrays, 1 tatf, 4 large loaches. but you also have to account for my tap water only being 5



Fish rookie said:


> 21 is very low...is it a barebottom tank?


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## Fish rookie

That is very interesting, thanks for sharing this info. 
Very awesome you can keep the tds so low with your system even with all these fish that you have. Your system must be working if you can keep the tds that low constantly. 
I must have missed something when I said I thought a drip would not work very well. Need to give this a try some day.
I think we can all agree that 50% twice a day water change is not the same as a 100% water change a day because with 50% you still have 50% waste in the tank after a water change and the new 50% will soon be polluted so you never have 100% new water at any time. I thought a drip would be similar.
But from the data you have provided it sounds like the water of your tank can be kept very low in dissolved solid with your drip system...do you think it is because your tank volume is large so you have more dilution?


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## MEDHBSI

Fish rookie said:


> That is very interesting, thanks for sharing this info.
> Very awesome you can keep the tds so low with your system even with all these fish that you have. Your system must be working if you can keep the tds that low constantly.
> I must have missed something when I said I thought a drip would not work very well. Need to give this a try some day.
> I think we can all agree that 50% twice a day water change is not the same as a 100% water change a day because with 50% you still have 50% waste in the tank after a water change and the new 50% will soon be polluted so you never have 100% new water at any time. I thought a drip would be similar.
> But from the data you have provided it sounds like the water of your tank can be kept very low in dissolved solid with your drip system...do you think it is because your tank volume is large so you have more dilution?


I don't think it's the size of my tank I'm only changing like 76 gallons per day and that's mixed old water and new water. So I'm changing less than 40% a day. I've never had happier healthier fish. But I also have fish that come from very low pH waters so me dripping 6ph water into my tank is perfect. I've thought about adding things for hardness and what not but until I see issues I'm staying coarse. My tank had been running since I bought it off Dino.


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## Vancitycam

Drips keep stability. Look up this koi keeper "crazy Andy" he can grow out so many koi in an "over stocked" setup all beautiful healthy and happy, his saying is "always changing the water but you never change the water" but he's just using a simple top of stream drip then pond over flow. Same idea.


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## dino

Just some info my Tds is high not sure if its all the minerals in my water or what but it's 65 out I the tap. I'm running drip in the discus and it's the same in the tank and they love it so far.


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## MEDHBSI

Its definitely because your water is high in minerals being all the way out in the whack. The only way i know of to get your tds lower is with RO water but 65 is nothing i would worry about. In vegas the tds is around 500-700. I only use 1 carbon and 1 sediment with my drip.



dino said:


> Just some info my Tds is high not sure if its all the minerals in my water or what but it's 65 out I the tap. I'm running drip in the discus and it's the same in the tank and they love it so far.


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## smccleme

One other thought on the drip versus weekly changes. About 6 months ago I separated 4 blue dolphins. I put two in the 155g with the drip, and the other two remained in the 125. They were all about the same size. The ones in the continuous water change tank are significantly bigger now. I do believe one in the 125g is a male, so I don't think it's a male/female thing. And that is also with the 155g tank only receiving one feeding a day, while the 125g gets two (both NLS). Lesson from this little story, if you want to grow your fish faster, feeding more doesn't appear to be the answer - waters changes/quality play a bigger role.


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## Fish rookie

That is very interesting, thanks a lot for sharing your first hand experience. Appreciate it.


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