tds table

[kaz]

Hello

I read a post not that long ago that gave a link to a TDS table. Does anyone have this link? I cant find it

I have had a TDS meter for xmas! (as requested ) and have tested my tap water (85ppm) and my tank water before (154ppm) and after cleaning (132ppm) - I was hoping this is ok and needed to check against a table of some sort.

Any help gratefully received!

Happy Xmas everyone!

Kaz

[Tinman]

I don't have a chart but thats very low, We are about 500-600 ppm here tap ,my fish are in about 400 through peat softening. ....The trick is to figure what the ppm are ,we can look at our water company here online and they can account for most on their website. You are lucky to have those numbers.

[Diana]

Ditto, very soft water.
Mine comes out of the tap in the upper 200s and the tanks are mostly throughout the 300s, except for the hard water tanks (800-1000) and the brackish water tank (2000+).

I do add aquarium plant fertilizer to the tanks, which is why they are higher than the tap water.

During the summer I was doing more topping off and the soft water tanks were over 500.
I added rain water as soon as it started raining, and things are back to normal now.

[chefkeith]

There is a table on this website-
http://www.msnusers.com/LyreTailsAquari ... olids.msnw

That tap water you have is nice and soft. Keep an eye on it though because it could change without warning.

It seems you have plenty of "extra stuff" in your aquarium water. You might want to try to determine the cause of it. It's usually from either fish waste, leaching, or evaporation.

[kaz]

It seems you have plenty of "extra stuff" in your aquarium water. You might want to try to determine the cause of it. It's usually from either fish waste, leaching, or evaporation.

Thanks. So, should I try to be getting my 'ppm' to roughly the same as my tap water?

I do have a root in the tank, but it has been in there since July. I also have 2 new coconut shell halves put in last month (boiled up until the water went clear, put into tank water in a bucket for a while before adding to the tank) Would this cause the 'ppm' to rise?? = 'extra stuff'? Or perhaps I need to do an extra water change per week? (I do approx 25 - 35% water change once a week at the moment - all nitrate etc levels are normal before and after water change)

Kaz

[Diana]

Keep up your regular water changes and an eye on it. If the TDS continues to rise then you may want to do larger water changes. Your tank has plenty soft enough water for the fish, not a problem there, it is just that if the TDS keeps rising it may level off at a level that is too high, then it is a bit of work to lower it back down again.

The only way the TDS will equal the tap water is if you do 100% water changes, or use RO water. Do not do either. Your water is fine where it is.

Here is how the math runs: (Numbers do not actually match your numbers, but look at the concept: The changes in TDS become stable, at some number higher than the tap water)
Each week you add minerals from fish food, fertilizer, dechlorinator and any rocks or other things dissolving in the water. Lets say all this put together adds 15 ppm to the TDS over the period of a week.
At every water change you remove 25% of whatever has accumulated, and add back the minerals in the tap water.

week 1 (set up)
85 ppm from tap water, add 1 week of fish food, fertilizer, etc, = 100ppm.
Week 2: 25% water change, removes 25ppm of the TDS (25% of 100 ppm), add back 21ppm with tap water and 15ppm through the week = 111ppm by the end of the week.
Week 3: remove 28, add 21 + 15 = 119
Week 4: remove 30, add 21 + 15 = 125
Week 5: remove 31, add 21 + 15 = 130
Week 6: remove 32, add 21 + 15 = 134
Week 7: remove 33, add 21 + 15 = 137
Week 8: remove 34, add 21 + 15 = 139
Week 9: remove 35, add 21 + 15 = 140
Week 10: remove 36, add 21 + 15 = 140
Condition is stable, and will cycle around 140 before the water change and 104 after the water change. Even if your numbers are a little different the concept is there: Every week you are adding to the TDS in the tank, and removing some of it with water changes. At some point it will stabilize. Find that stable point. Monitor it. If it ever changes start looking into why? Has the tap water changed? Are you adding more plant fertilizer? More fish food?

If you need to top off during the week and you use tap water you are adding more TDS to the tank because water that evaporates is leaving behind the minerals. If you need to do a little topping off here and there it is not a big issue, but if it reaches a point that you see the TDS is climbing too much then you may want to top off with reverse osmosis, distilled, or rain water. (These have no minerals and will reset the TDS lower in the tank)

[chefkeith]

Thanks. So, should I try to be getting my 'ppm' to roughly the same as my tap water?

No. Some of the stuff is essential to the micro organisms in the tank. Since we both have soft water, we can probably use the same water change philosophy. I try to keep my tank water within 25 to 40 ppm of the tap water. When the difference gets higher than 40 ppm, I know it's time for a water change.

Right now you are at 154 - 85 = 69 ppm difference before a water change
and 132 - 85 = 47 ppm difference after a water change. So your TDS difference is a little bit high.

(For other folks, remember that this doesn't apply to hard water. Hard water would need a larger and wider TDS range.)

I do have a root in the tank, but it has been in there since July. I also have 2 new coconut shell halves put in last month (boiled up until the water went clear, put into tank water in a bucket for a while before adding to the tank) Would this cause the 'ppm' to rise?? = 'extra stuff'? Or perhaps I need to do an extra water change per week? (I do approx 25 - 35% water change once a week at the moment - all nitrate etc levels are normal before and after water change)

Kaz

You'll need to figure them things out.

I don't know if the root and coconut shell will make the TDS rise. Here's a simple test you can do- Just put one of the coconut shells in a sealed container of water, like a zip lock plastic bag, then test the TDS, then wait a week and test the TDS again. If the TDS goes up, then you know that the coconut shell is a contributor to the TDS going up. I wouldn't worry about the coconut shell though. Just because something adds to the TDS that doesn't mean that it is necessarily bad.

If you have rocks in the tank, you'll want to do the same test. Rocks leaching is usually bad.

If the tank is not covered well, then evaporation is another contributor to why the TDS difference between the tap and the tank is a little high.
How much water evaporates from the tank each week? How much water does it take to top it off? If it's a good amount, then you'll need to top off the tank a few times each week if you don't already.

What is the normal nitrate level?
How big is the tank? What is the tank stocked with? How much do you feed the fish? Are there plants in the tank? Do you add fertilizers?

Anyway, You probably should do more than one water change per week. Two 20% water changes per week is what I usually recommend.

[kaz]

Diana/ Chefkeith

Thank you so much!

I will let you know of my findings with the rocks in the tank.

I will do 2 20% water changes instead of my usual 1 x 25%.

Thanks again
Kaz

[kaz]

Numbers do not actually match your numbers, but look at the concept: The changes in TDS become stable, at some number higher than the tap water

Hi Diana

I have done some calculations thanks to your advice.

If I do 2 x 20% water changes every week - in 5 weeks time (if all goes well) I should find the TDS becomes stable at approx 123ppm. This would also give me the 25 - 40ppm difference that Chefkeith mentioned. 85ppm for my tap water plus 38 = 123ppm

Does this sound about right? Have I managed to follow the concept?

Of course I will check the rocks because I have a sneaky suspicion it is not going to be as straight forward as Id like!

I am hoping Ashleigh will still agree to take my loaches and I then should have a different story to tell. (Ashleigh if you are reading - did you get my messages?)

Thank you everyone

Kaz

[chefkeith]

kaz- here is a water change calculator that you try using-

http://www.geocities.com/chefkeithallen ... izard.html

[kaz]

kaz- here is a water change calculator that you try using

Thank you

Kaz