this and that

[fishgeek]

couple of questions

1. my r/o unit produces water that reads 0 ppt and 0ms on the hanna combi meter and has a pH of 8.5 , any suggestions for what is in the water making it so alkaline?

2. How do you equate an EC or TDs reading with hadness , i seen a suggestion of 17ppm as being equivalent to 1 kH (or poss gH) does that seem about right
and would that make my thing that 0.17 ppt would be roughly the same ?
sorry :roll: my maths is a decimal place out , scratch that question

can i still say 0.02 is roughly 1 kH on my meter?

3. until what age,size can the sex ration of fry be manipulated

Thanks
andrew

 

[Discus Man]

any suggestions for what is in the water making it so alkaline?

Yes, OH ions, :wink:
Just becasue the R/O unit can pass water through, doesn't mean there will be a change in pH. There usually is, but in many cases pH takes time to change by absorbing C02 from the air, etc.
To force the pH of R/O water to go where I wish it to go, a tiny dose of Seachem acid buffer will set it to a nice pH of 6.2 I use a dose of about 5 grains per 10g of R/O water.
I can then add tap at a ratio to arrive at a pH of 6.6 and a KH/ GH of 4

hanna combi meters can't really be setup for testing hardness of R/O water, at least so I've been told as they just can't be calibrated that sensitively. (Now this was the sales person talking me out of buying one).

# 3, I have no idea as I keep my fry unitl I can sex a few and tend to sell the rest unsexed. Sorry, hopefully someone else can post on that one.

 

[tjudy]

No electric meter can accurately test KH because the carbonates that cause KH are poor cunductors of electricity. You can test this by taking your pure water and adding calcium carbonate to it. The TDS will not increase a lot (some because calcium carbonate always has some calcium chloride in it unless you buy reagent grade calcium carbonate), but your pH will go through the roof.

You can also add pure sodium chloride and watch the TDS go way up, but the KH will not change. NaCl totally dissociates into ions that the meter can read.

GH is a measure of general hardness, and is measuring the same thing as TDS... so a conversion factor would work, though I do not know what the factor would be. GH is not KH, however.

 

[2la]

http://www.hydroponicequipment.com/diptest.shtml

 

[fishgeek]

The TDS will not increase a lot (some because calcium carbonate always has some calcium chloride in it unless you buy reagent grade calcium carbonate), but your pH will go through the roof.

could that suggest that my r/o does not remove all these carbonate ions?

long shot i know and the quick dipsticks i use(unknown accuracy) show a very low hardness in the r/o

i think i will calibrate and play with it and some other froms of measuring hardness to see if i can work out a conversion for my water

what readings do those using a similar meter get for there water
my lowest readings are0.10ppts and 20 ms(or is ths us) i'm not so sure this is particularly soft any more
although i did have a small 10 litre tank with a small (fist size) piece of wood in where the pH got down to 4.5 so cant be too hard

thanks for the answers

 

[tjudy]

I have an RO/DI unit. The deionizer is what gets my pH to 7.0. Carbonates, if there are a LOT in your tap water, will get through RO alone, but not usually both RO and DI.

 

[Peter Lovett1]

RO unit remove about 95% of all dissolved solids.

If you start out with water that has 200ppm when it goes though the RO unit you will get 10ppm. If you water like mine, is mostly carbonate hardness.

Mine is about 260ppm carbonates and about 50ppm of other stuff.
After the RO process I am still left with 13ppm carbonates and 2.5ppm other stuff.

I also use a deionizer which gets the water down to 0ppm.

Also RO water out of the hose is super oxygenated. This is because oxygen passes though the RO membrane very well where as CO2 does not. Which lead to a temporary rise in PH. After about an hour it should be about a ph of 6.5 or 7. If it is not then I would think about changing your Carbon filter and membrane.

 

[fishgeek]

it is an r/o d/i unit 4 chamber
i am on pretty hard water , not exactly certain of all the salts and do know that calcium mg and phosphorus are all quite high
the water runs into a butt and sits for days before being used so i dont think it is a dissolved gas reason although that would make sense of the no dissolved solids and pH issue

is the dissolved oxygen combining with H+ ions to increase the pH ?
not sure i uderstand it all at present and do know that the fish are happier several spawns and succesful hatches so they must like the water

Any answers on the sex determination part?

andrew