Conductivity, when to do WC - The Planted Tank Forum
 
LinkBack Thread Tools Display Modes
post #1 of 10 (permalink) Old 10-17-2012, 08:02 AM Thread Starter
Algae Grower
 
PTrader: (0/0%)
Join Date: Apr 2012
Location: w-europe
Posts: 27
Conductivity, when to do WC

This whole EC-thing is pretty new to me, so I apologize if I sound like an idiot. I bought an EC-meter. Specs of tap water are GH 4-5 (now, changes quite alot between 4-7), pH now 7,4 (usually 8), KH3 (-5), EC ~620 (microSiemens/cm, oh my, this high was a bit surprise!). Aquariums (four) GH7, KH3, pH 7-7,2 EC 750-850 (11 days after last WC 30%). NO3 and PO4 are really low now, I use a bit some ferz (K, Plantex, Fe, Equilibruim and Excell daily). Tanks are full-mid planted low-techs, mid stocked I suppose. GH keeps going down ~1dh per week so I must add it a bit regularly.

The question is: when to change water? How much I can let EC to raise before WC? 100 microsiemens, two? I have tried really hard to find the answer from net without luck. NO3 is so low it cant be the factor, EC keeps going up from day to day so it must be that.

For sure the water is not very suitable for soft water fish species wich we also have (Amazonian and Asian species) among bows and blue-eyes but fish has done well so Im not sooo worried about the tap water. On the other hand Id like to keep the water as clean as posible in this situation when the water is not so ideal for all fish. Im considering to give away soft water fishes but since they have been fine, maybe just not to buy them anymore, just hard water species? Other specs than EC are fine for soft water species (in their own tanks) and med-hard water species (in their own tanks) but the conductivity is hardly OK or med-hard water species! Confusing!
Itwasntme is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old 10-17-2012, 04:15 PM
Planted Tank Guru
 
wkndracer's Avatar
 
PTrader: (68/100%)
Join Date: Mar 2009
Location: Citrus County,Florida
Posts: 6,186
I use a clean water reference here.
When I set tank parameters including any fert dosing I'll wait until the following day then test tank TDS recording the value. When the tested value increases 100ppm over that value I generally do a 50% WC. With life getting busy I may miss that mark but never much more than 100ppm above clean.

HTH


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

If at first you don't succeed,,, keep kicking it
RubberSideDownOnTheLanding,
2-75g planted, 3-55g planted, 110g w/30g sump, 2018 update returning to sanity (Nutz)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
wkndracer is offline  
post #3 of 10 (permalink) Old 10-19-2012, 04:56 AM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jan 2010
Location: Contra Costa CA
Posts: 11,721
I do not know if it is a specific value, or, like wkndracer you simply keep track of it and do enough water changes to keep it within certain values.
Diana is offline  
 
post #4 of 10 (permalink) Old 10-19-2012, 07:49 AM Thread Starter
Algae Grower
 
PTrader: (0/0%)
Join Date: Apr 2012
Location: w-europe
Posts: 27
Thank you. This is so confusing because it is said its good to check your WC-regime with the help of donductivity, but how to do it, is not told anywhre!

wkndracer: what you are saying, sounds good to me. What is the "starting level" of your aquarium? I guess the same as tap water EC? I mean should I do soooo big WCs that the tank is as close to tap as possible, for example 650uS or so, then add fertz and start counting from that? After last WC (50%), EC was after adding fertz~720, 100 more than tap water EC, so it did not have very much effect on EC wich was before WC ~780. Hard to explain, hope you understand what I mean? The good news is that EC doesnt seems to raise a lot in a period of week.

Im not sure but if I can remenber right Joe Gargas, the legendary discusbreeder, has said somewhere that EC can raise 50% till WC has to be done (or earlier of course). In my case it will end up ~900 wich sounds..........................high?!!?

I wonder what raises EC here since other prams are not that high (or are they?). Sometimes we have pH8, KH5 and GH7 at highest, what would the EC be then!?!! The city near ours has almost same water prams but EC just ~200. Oh so wrong! Oh, why did I bought the meter?!
Itwasntme is offline  
post #5 of 10 (permalink) Old 10-19-2012, 03:34 PM
Planted Tank Guru
 
wkndracer's Avatar
 
PTrader: (68/100%)
Join Date: Mar 2009
Location: Citrus County,Florida
Posts: 6,186
I'll try not to confuse things further. That being said, it's a bit complicated with any number of variables to cover in a short forum post. The situation I'm in here I have the greatest control I can manage over water parameters using an RO system. When I add water to replace for evaporation or doing a water change I don't add any mineral or organic content with the water. Minerals are added separately in another function of my maintenance setting water parameters.

Using tap water for top off replacing for evaporation or doing partial water changes TDS test results will gradually rise over time. Is this a huge concern? I don't think it is and it can’t be helped. We can't really solve that dilemma without draining and restarting the tank.

You have to realize and accept that as water evaporates the mineral content is left behind. Doing partial water changes with tap water you add 'new' water replacing a portion of the tanks volume but also add more ‘new’ minerals doing so. Feeding the fish and plants and everything else we add to the tank affects TDS. Plant growth removes some of this from the water column and in turn trimming plants we remove those additions from the system but it's not a 1:1 ratio by any means.

Simple example for explanation; Fill an open container with tap water, test TDS and then allow 10% to evaporate. Without ‘adding’ anything to it TDS values will have risen on the remaining water volume. Drain off 50% of that water and refill to the original full mark and test TDS. It won't match the first test result but will be slightly higher,,, make sense?

Doing a 50% by volume water change you will reduce the organic build up of suspended and dissolved solids by a roughly equal 50%. Filling with tap water though the TDS reduction will be only a fractional change due to the mineral content of the tap supply. This will be the new freshwater TDS reference point,,,
hoping that makes sense in translation?

Knowing you just replaced 1/2 the water with 'new' or 'clean' water that is the new reference for TDS not the original from the first fill on the system. Many, many people maintain tanks this way without issue or ever understanding the slight changes that occur.

Simply do the cleaning and water change, record the TDS value the following day as the new starting point and as the monitored level increases again by 100uS or what you have determined the threshold shift to be then repeat maintenance and record the new 'clean' value.
No living thing has a static value so don't expect it. Establish set point values and routines then just enjoy the hobby.

You mentioned Joe Gargas (I smiled), he lives south of me by about 1 1/2hrs by car. I've visited his hatchery and purchased fish from him. (wonderful guy to deal with)
His hatchery filtration system is impressive and was a tour of education to examine.
Tap / RO input, calcium reactors, fluidized sand beds, UV units, sock filtered sumps, spun fiber filters and central return head tanks,,, amazing and very compact foot print.

Hope This Helps


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

If at first you don't succeed,,, keep kicking it
RubberSideDownOnTheLanding,
2-75g planted, 3-55g planted, 110g w/30g sump, 2018 update returning to sanity (Nutz)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by wkndracer; 10-20-2012 at 01:27 AM. Reason: remove font coding
wkndracer is offline  
post #6 of 10 (permalink) Old 10-19-2012, 03:59 PM
Planted Tank Guru
 
PTrader: (33/100%)
Join Date: Jul 2011
Location: Gone
Posts: 5,994
Mike great post.

To the OP. Testing perimeters is a tool to help use understand were we are in our tanks. All of our tanks are unique from our local water to the choices of what we keep in that water. What works in terms of TDS, PH , Temp etc in one tank may not work so well in another. It's a matter of understanding your situation.

For me a 25% tap water change 3Xs a month with a 1X a month 25% RO water changes is working very well.
DogFish is offline  
post #7 of 10 (permalink) Old 10-19-2012, 04:49 PM
Planted Member
 
rrastro's Avatar
 
PTrader: (1/100%)
Join Date: Jun 2012
Location: El Cerrito, CA
Posts: 276
Quote:
Originally Posted by DogFish View Post
All of our tanks are unique from our local water to the choices of what we keep in that water. What works in terms of TDS, PH , Temp etc in one tank may not work so well in another.
Yeah, that.

Another thing that warrants mention here is the conversion factor from EC to TDS. In America we tend to refer to TDS which is not an objective measurement because various meter manufacturers have different conversion factors when changing the EC measurement to TDS. Common conversion factors include .5, .64, and .7 so that an EC measurement of 400 uS could be 200 ppm, 256 ppm, or even 280 ppm. Temperature compensation may or may not be a feature on any given meter and that too can add variability to what we think we know about the EC or TDS of our tanks.

Easing my toes in the water
SFBAAPS Member
rrastro is offline  
post #8 of 10 (permalink) Old 10-19-2012, 05:23 PM
Planted Tank Guru
 
wkndracer's Avatar
 
PTrader: (68/100%)
Join Date: Mar 2009
Location: Citrus County,Florida
Posts: 6,186
While all that is true if you are using the same device each time to repeat the testing process it matters very little. Whether the device has temp comp or not you still monitor for a shift in the recorded value to trigger events. Using the same device each time the error in value will be a constant. The pen I use to track tanks hasn't been calibrated in 2 yrs. Whether the zero is precise or not doesn't matter to me because all I want to see is range of shift in values not lab quality results. The inlet and outlet meters I use on my RO system now those I cal. every 6 months because yield ratio and product TDS is how I replace filters. (like all posts this is just my opinion)


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

If at first you don't succeed,,, keep kicking it
RubberSideDownOnTheLanding,
2-75g planted, 3-55g planted, 110g w/30g sump, 2018 update returning to sanity (Nutz)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by wkndracer; 10-21-2012 at 10:19 PM. Reason: word
wkndracer is offline  
post #9 of 10 (permalink) Old 10-21-2012, 03:43 PM Thread Starter
Algae Grower
 
PTrader: (0/0%)
Join Date: Apr 2012
Location: w-europe
Posts: 27
Thank you, wkndracer, again. You really offered something new to think about and you are right. RO-unit in no-no for me but let me explain a bit how I found myself thinking of this EC-thing. I came from high-techs to lows in spring because we had TONS fo problems with technic and finally I got tired of it. Now I like these low-techs really much and everything has gone just fine. But about two weeks ago nitrarate came down to 1-3ppm, earlier they were ~10 before weekly WC. P is very low too, hardly measurable. My target is to do as little as possible but I will, and want to, do what I have to do, no doubt, for fishes and their wellnes. I thought everything is fine since nitrate and P are so low (maybe I can do WCs once a month?!?) but then I got the SuperIdea to buy an EC-meter to check how things really are. Here we are and I still dont know to to handle this because the EC is soooo high from tap. Of course doing 50% WCs is the answer as you state, but my target was/is keep these low-maintenance tanks. I thougth buing EC-meter would answer the question of good WC-routine for my purpose. Why to measure EC if I cant use the information it gives to me? yesterday EC was 720, today 726, next week 780, whens the right time to reset the tank with WC...

This is not a big issue to me, Im just keen on to learn more. Fish seems to be fine. Im just trying to create new routines and seach tools for it.
Itwasntme is offline  
post #10 of 10 (permalink) Old 10-22-2012, 09:07 PM
Wannabe Guru
 
PTrader: (29/100%)
Join Date: Mar 2010
Location: Jersey Shore
Posts: 1,167
In my one high tech, soft water planted tank (kH 1; gH 5), I generally do a water change when the TDS exceeds 250 ppm (on the NaCl scale).

The TDS value following a 75% water change is generally around 150.....


BTW, seeing that you're from Europe, keep in mind that we use a different EC scale over here in the US.
snausage is offline  
Reply

Tags
None

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome