RO/DI Water TDS Testing

[DyeLooper]

All,
I have a 75 gallon fish only tank, just finished cycling about 1 month ago. I have a small load in it, 4 damsels and a Coral banded shrimp. I’ve been using RO/DI water from a Kent HiS 60GPD system. When I test for silicates I get about 1 ppm in the tank water and at the ro water. The tank does show signs of silicate by having the slight red/brown algae and the slight stink that it gives off. I just got my TDS meter today, the RO/DI reads about 25ppm. I’ve heard this is to high and people don’t change out the DI bed until 30ppm. Any other input? When I hooked up the RO/DI unit, I now I messed up and never pulled the DI cartridge for the first initial 12 gallons as the instructions stated. Could this be where I’m getting the silicates from? Do I replace the membrane or the DI cartridge? Any help would be appreciated.

Temp-78.5-78.8
Ammonia-0
Nitrite-0
Nitrate-0
Phosphates-0
Calcium 375-400
Salinity 1.023


Thanks
DyeLooper

[tendar]

Replacing your DI cartrige should bring you sil down to zero.
How ever what you need to do is check what your tap water is before going to your ro/di unit to see just how bad your water is (here in phoenis it usally runs around 600ppm pretty bad)then check and see what your water is coming out of RO unit before the DI to see if you need to change all your filters or not. Just replacing the DI will help for now but if your other filters are shoot the DI will burn out fast.

[DyeLooper]

Gregg,
Thanks for the reply, my incoming water is in the 240ppm range, havent tested after the ro membrane yet, will do soon. Thanks again

Jason

[Katspaw]

geez guys ya'll are lucky. I tested my tap water here in Jersey and it read 999 and flashed. As per manufacturers instructions that means it is over 1000ppm. :eek: With the new six stage Ro/DI I have now, my RO water is at 0ppm. We did some testing on various bottled waters around here and Great bear did the best at only 100ppm.

Tracey

[tendar]

240 is pretty good for tap water.

[DyeLooper]

WOW!! Thats smoking, great you have a good system to get rid of all that crud. Tested my good water today and was getting 0 ppm. Could when I'm making to much water the TDS rises slowly? I'll have to keep an eye on it. I now my bulbs are quite old, could that lead to Diatom blooms to then cause the silicates? My tap water is 240 but high in silicates, go figure!! This site is great!!

Thanks

DyeLooper

[tendar]

I have noticed the same thing when I making a lot of water after a while the tds will rise some but after it sits for a while it drops back to 0.

[brody98]

Mine will also read 1-2 for a day then read 0 after it sits for a while, tap water here in cedar rapids is 160-190, but tastes like crap :-)

[DyeLooper]

These are great ideas, I will have to look at this, thanks.

DyeLooper

[tendar]

Cedar Rapids I was born there and grew up in Mason City.

[deepblue68]

what do i use to test for tds other then the kent tds meter and where can i buy the test kit.
thanks

[tendar]

You can get TDS hand held meter for around $35-40 to test tds there is no actual test kit.
Some thing like this
http://www.aquariumwaterfilters.com/Instruments/TDS.html

[DyeLooper]

I just got mine from E-bay, got it delivered for 24.50, works great.

DyeLooper