Backyard Aquaponics
A place to discuss aquaponics

I went looking on the net tonight for some sodium thiosulfate to dechlorinate my tap water since I'm running out of the expensive water ager I bought at the fish store. But this is weird. Most places sell 5gal buckets of the stuff for somewhere between $100-200US. But this photography place has two prices:

Photographer's Formulary Sodium Thiosulfate (Pure Hypo), Pentahydrate -
http://www.adorama.com/PYST1.html?sid=122222146010269
1 pound / $5.00 US

Photographer's Formulary Sodium Thiosulfate (Hypo), Pentahydrate -
http://www.adorama.com/PYST100G.html?si ... 2235358409
100g / $5.00 US

Adorama looks like a reputable place - it has google checkout, and sells through Amazon.com, so I'm tempted. But am I missing something? Is it cheap because pool places regularly mark things up by 100%? Or is the chemical different and I'm going to kill my fish?

Its much cheaper to have the water sitting in a big bucket or barrel with an aerator in it.

I dont know anything about dechlor chemicals - I dont use them.

ive been using VitC as de-chlor for MAJOR water changes and for my marine tank top ups

10% topups of AP i wouldn't even worry about!

Well I wasnt gonna say dont dechlor at all - I got in trouble last time

But I agree, 10% of total system water does not appear to do any harm. or 90% lol

the way i figure if the water is at 2ppm then a 10% change will leave you with 0.2ppm

I wouldn't do a 90% change with tap.

Wouldn't a 10% change remove 0.2ppm.... not reduce it to 0.2ppm.... :dontknown:

I prefer aging water as well, but I now have three systems, and really only one 55gal watertank to store water. And it's inside. So I need something for when HSM strikes... Also, hard to age water in UV when the temp is -20F.

So, I want to buy for emergencies and, well, winter.

rupe, if i have a 1000l tank and remove 100l then i have 900L

if i then add 100L of tap water that contains 2ppm chlorine then i have added the 2ppm chlorine in a 9:1 ratio. 11%

11% of 2ppm is .22ppm chlorine in the 1000L tank. i think

Ah... OK... I thought the tank was measuring 2ppm ... and you were replacing 10% of the water to dilute...