Help with my water

[smgracey]

I have some questions concerning my water, I have been reading about it for the last couple months and just can't seem to get it! Ok so let's start with one of my tanks it's a 20 gal long planted tank with sand substrate (no dirt), a spawning cave, driftwood and 2 sponge filters it houses a female apistgramma cacatuoides and 5 fry. My water is from a well and from the tap it has no tds (testing with a blue lab tds meter) and no gh or kh ( testing with api gh and kh kit) and a ph oh 6.4( tested with blue lab ph meter). I use sea chem alkaline buffer to raise the kh then sea chem acid buffer to bring the ph back down to 6.5 it leaves me with a kh and a gh of about 5 degrees each. After a day or two my ph starts creeping in the upper 7's almost reaching 8 I can change the water again and get the ph down but in another day or two it's back up.
What am I doing wrong and how can I fix this. Please remember that I'm a plumber not a scientist so explain in plain terms.
Thank you in advance for any info
Sean

 

[Mike Wise]

Personally, I think you're 'playing chemistry set' with your tanks. Maybe try to use your water without additives and then test after a couple of days. I'd also be suspicious of any well or tap water that test with 0 TDS. Such values are even hard to get with RO/DI units. Have you calibrated your meters lately?

 

[smgracey]

yes I calibrate my meters regularly and use them almost daily as I keep a lot of house plants, I also get the same readings from the APIs test kit that I have it is only about 2 months old so I think it is correct. My house plants suffer from lack of cal mag and have to add it for them with my nutrient regiment.
Doesn't lack of kh cause health problems for the fish?

 

[Mike Wise]

0° dKH yes, but that isn't likely to exist for long in a biologically active environment. Most foods add Ca in some form. I still don't understand how water percolating through any substrate, like water from your well, doesn't pick up some minerals.

 

[dw1305]

Hi all,
Something isn't quite right, as Mike says it is almost impossible to get ground water with no solutes in it, mainly because water is a very efficient solvent.

Although it is a TDS meter it actually measure electrical conductivity, with 100 microS converted to ~64ppm TDS.

Is there an option to change the scale on the meter? 1 milliS is 1000 microS, if the scale is set to millisiemens it will record very low values even if their are solutes present

If you add a very small amount of table salt to the well water you should see the TDS (really electricity conductivity) rise really quickly. As an idea of how little you need a 10 μS/cm rise in conductivity is equivalent to about 6.4 mg of NaCl per litre of water, and a teaspoon of salt weighs about 6g (6000 milligrams).

I'm not a great fan of buffers, partially because pH isn't a very useful measure in very soft water, and when you get to pure H2O it is meaningless. A lot of people extrapolate from their experience with Rift Lake Cichlids, where changes in pH are caused by large changes in water chemistry, to soft water, but it is different in all systems with little carbonate buffering pH will naturally fluctuate because very small changes in water chemistry cause large changes in pH.

You can add some hardness (both dGH and dKH) easily, you don't need to use the buffers. "Epsom Salts" (MgSO4.7H2O) are a useful source of magnesium (~10% Mg) and you can add calcium via a small amount of "oyster shell chick grit" (CaCO3) or calcium chloride (CaCl2) or Gypsum (CaSO4.2H2O).

Do you feed your tank plants? if you do then your fertilizer should add some magnesium.

cheers Darrel

 

[smgracey]

I agree with the both of you that it is not normal to have water with 0 tds But that is what I have and I have to learn what to do with it.
About 4 months ago I replaced my meters as they were getting old and still got the same readings.
My blue lab meter does have an option to change from 500 tds to 700 tds and to ec. Not sure if that is miliS but they all have the same reading 0.
Yes, I do see a change when adding salt to my water. Is this just a test to see if my meter works because as I said I calibrate it regularly and use it almost daily to mix nutrients to a certain ppm for my house plants.
I have done a ton of reading online about this and from what I can understand after weeding through a lot of crap and repeated info the sea chem products are basically the same as the Epsom salts and calcium chloride I'm just paying more for them.
In 3 of my tanks I have just a sand substrate and I use root tabs for the plant in them my fourth tank has dirt under sand using the waldstat method to the best I could understand it the book goes a little above my head on some topics. I have not seen any problems with the plants so I have not added any ferts to that tank yet.
All my fish seem happy its mainly the one tank with fry that I'm concerned about from what I have read in the cichlids atlas v1 there is a correlation between fry sex, temp and ph. Since I lost my male after the eggs where laid I want to stay in the range that gives me an even sex and not where I'm going to get just females.
Thanks for working though this with me I appreciate all the help I can get.
Sean

 

[regani]

There are different TDS meters around for different purposes and some of the ones for hydroponics applications are high range so you may not get a reading for low TDS water as Darrel pointed out. What TDS value does the calibration solution have? and is that at the high or low end of the readings on your meter? If you have brand and model number that may help to find out more.
The pH fluctuations could be from something in the tank - this is usually the case when the pH goes up. Are there stones in there that might be sandstone or does the sand contain some shell grit, maybe? You are using sponge filters, that rules out filter media (some of the cheap ceramic ones can be quite alkaline).
If your water has a nice low TDS you should keep some of the more unusual apistos, not just cacatuoides ;-)

 

[smgracey]

I did not know there was a high and low tds meter but my api gh and kh test kit should be able to test low correct?
When I do the gh test after 1 drop turns green and my kh test after 1 drop turns yellow I don't even see any orange or blue.
Here is a link to my tds pen. https://www.bluelab.com/products/type/pens/ec-ppm-pens
Here is a link to my ph pen. https://www.bluelab.com/ph-pen
Here is a link to my probe care kit. https://www.bluelab.com/products/type/probe-care-kits/ph-and-conductivity-probes
I did have some slate in my tank but thinking like you I had removed it to see if it makes a difference and it did not.
My sand I got at my lfs (unfortunately it's a pets smart) it was the only black sand they had and it is the national geographic sand I don't think it had any she'll grit in it but not 100% positive I think shell grit would be white and I would see it pretty plainly in the black sand but I could be wrong.
The only other thing I have in there is a commercial cichlids cave. Not sure what it is made of I guess some type of clay or something like that.
Here is a link to that http://www.kensfish.com/aquarium-su...plies/stackable-grey-jumbo-spawning-cave.html it was bigger than I thought so I broke it into smaller caves
Yes my low tds water is what started me looking into apisto's and I figured I would start with the cacatuoides it seemed like one of the more forgiving apisto's before I started in on something a little harder.

 

[smgracey]

I was trying to figure out why my water might not have any tds and I don't know if this has anything to do with it or not but I live next to a man made reservoir that was made by damming a large valley and letting it flood. I sit up the hill from the res but my well is deep enough to be down below the water line in the reservoir and is drilled about 100 yards from the water I'm not sure how far the water will push back into the sounding ground but I can only imagine that most of my water is being pushed back in from the res and not drained off into the valley like it did back before the dam (back in the 1940's I think)
Could this be the cause of the lack of tds?

 

[boofeng]

I have no idea what exactly is causing your pH creep, but I did experience something similar before. I used Aquael Aquadecoris fine quartz sand, which is labeled "won't affect pH" etc. Well I had nothing in the tank except wood, plants, HMF filter and the sand, but pH kept creeping up. This was also the time I was experimenting with citric acid as well as peat granules - so I can't isolate the sand as the cause. At that time, I had a bag of peat behind the HMFilter and was adding citric acid to get pH 4+, and over a week it would rise back to 7. Anyway, the curious thing is whatever was raising the pH back then seems to be gone now. I'm currently getting a consistent pH value of 4.5 (the lowest the drop test will read) from this tank. I no longer use citric acid, but there's still lots of peat in the tank. I'm guessing the sand wasn't pure, and something in it was raising pH, but whatever was there has been used up.

Because of this (and another sand tank acting similarly), I'm a little wary about aquarium substrates now. I'm thinking maybe a dilute acid bath for the substrate before use could be a good thing. I'll do that for my next batch.

 

[TuvaM]

With higher kh you get higher pH. That's probably why. Kh acts as a buffer for pH and makes it more stable, so low kh will probably make your pH less stable. But in order to keep a low pH value, you also have to keep the kh value quite low. Lower than 5.

 

[Mike Wise]

I'm currently getting a consistent pH value of 4.5 (the lowest the drop test will read) from this tank.

Actually you don't know what the pH of your tank really is. All you know is that the pH is below the limits of your test kit. It could be 4.5 - or 2.5 (or anywhere else below the detectable limit of your test kit).

 

[boofeng]

Actually you don't know what the pH of your tank really is. All you know is that the pH is below the limits of your test kit. It could be 4.5 - or 2.5 (or anywhere else below the detectable limit of your test kit).

Indeed! Thanks for pointing that out. I'm just glad it's not bouncing up to 7 after I bring it down to 4+ anymore!

 

[regani]

I had a look at the link with your TDS meter. It is one of the higher range ones intended for use in hydroponics. There the concentrations are much higher than in your regular fish tank, this is probably the reason why it doesn't pick up a reading when your TDS is low.
If your pH goes up there is something in your system pushing it up. It can be a pain to find that at times as every single thing has to be tested individually to be able to rule it out. Just assuming something shouldn't raise pH can easily lead you down the wrong track...