Topping off

[cprash]

I've been getting a ton of evaporation since I'm using a desk fan to cool my Ebi (7.9g). It's about a half gallon a day. Since I'm still concerned about water hardness, I'm thinking taking out another .5 g and replacing it with a full gallon of filter, aged water. Should I do that? Can I do that on (every/most/some/a few) days?

-Calvin

[Kunsthure]

Top off with RO. Even aged water has a TDS and you would just be raising the TDSin your tank, which isn't good.

If you live near a Target, its "purified water" is RO. $0.89/gallon.

-Lisa

[cprash]

Thank you, I've got a few Targets nearby and I'll have a look on monday!

[acitydweller]

Actually, replacing displaced tank water with aged tap would likely decrease overall tds since the relative tds of dirty tank water would be higher.

[AaronMB]

Originally Posted by acitydweller

Actually, replacing displaced tank water with aged tap would likely decrease overall tds since the relative tds of dirty tank water would be higher.

I'm a little confused.

While it seems that adding tap would be "dilution" of the tank's TDS, isn't it just concentrating the TDS because the water that evaporates out leaves their solids behind, ultimately raising the TDS (of what they would have measured before the evaporation)? So, while adding tap may technically dilute the TDS of the tank--from what they were before and after the top off--eventually, aren't we really just adding to the overall TDS of said tank?

I thought the only way to truly dilute it would be to use water with 0 TDS?

(An honest question, as I try to do my shrimp-keeping homework!)

[cprash]

Yep, wondering about this too. That was my logic for taking out a half gallon of tank water prior to the top off

Originally Posted by AaronMB

I'm a little confused.

While it seems that adding tap would be "dilution" of the tank's TDS, isn't it just concentrating the TDS because the water that evaporates out leaves their solids behind, ultimately raising the TDS (of what they would have measured before the evaporation)? So, while adding tap may technically dilute the TDS of the tank--from what they were before and after the top off--eventually, aren't we really just adding to the overall TDS of said tank?

I thought the only way to truly dilute it would be to use water with 0 TDS?

(An honest question, as I try to do my shrimp-keeping homework!)

[jcgd]

Yeah, that's right. The TDS will creep up. But it will reach an equilibrium after a few weeks or months depending on the number of top offs and the frequency x size of water changes. You may be able to live with it if you have somewhat soft water.

[acitydweller]

Originally Posted by AaronMB

I'm a little confused.

While it seems that adding tap would be "dilution" of the tank's TDS, isn't it just concentrating the TDS because the water that evaporates out leaves their solids behind, ultimately raising the TDS (of what they would have measured before the evaporation)? So, while adding tap may technically dilute the TDS of the tank--from what they were before and after the top off--eventually, aren't we really just adding to the overall TDS of said tank?

I thought the only way to truly dilute it would be to use water with 0 TDS?

(An honest question, as I try to do my shrimp-keeping homework!)

RO top off with little or no tds would work fine. this is already common practice for reef tanks. Sorry, i missed the part about evaporation.

[cprash]

thanks everyone, I have a pretty good idea of what to do now. I'm on a winning streak with this tank so I've got to do everything possible to avoid hurting my shrimpies.

-Calvin

[GeToChKn]

There is many ways to do this and each keeper/breeder has their own way that works for them.

Some just top off with pure RO all the time which roughly keeps the TDS the same with a small creep over time. They usually run multiple canisters together to get nitrate removal going though so they don't have nitrate creep and don't usually change much at all.

Some just let the water get low and change it with their target TDS water.

Some top off with a very low TDS mixture to get a bit of fresh minerals in the water and then change every few weeks.

Some just top off all the time with their normal water and let it be. TDS may be very high but the shrimp breed in it fine.


As you can see, there is many ways to do it and whatever makes your shrimp happy and breeding, go with it. I've bought shrimp that have come in 110TDS water and 600TDS water. Both those figures were working for both the breeders.

[cprash]

Been testing gH and kH got an (expected) blank stare when I asked my LFS about a TDS tester. What do you guys use?

-Calvin

[GeToChKn]

Originally Posted by cprash

Been testing gH and kH got an (expected) blank stare when I asked my LFS about a TDS tester. What do you guys use?

-Calvin

I got a ebay one from China. you can probably find them for a bit more on Amazon and not have to wait a month like I did. Most places on Amazon don't ship to Canada, so I have to order from the-bay instead. Look for something with ATC ( automatic temperature control) which work out better because they adjust the TDS reading based on temp. If your tank is hot or cold outside the range the meter is to work in, it will give a different reading (not a lot mind you, but they're usually only a few bucks more for a better one)

[h4n]

This is the one I use:

http://www.amazon.com/HM-Digital-TDS...ords=TDS+meter

$20 shipped, works fine for me! And i know plently of people on here who use the same thing.

EDIT: that one I linked does have ATC, it just doesnt say no the decription. As most amazon item decription are vague. It actually say it on the box in comes in.

[cprash]

Originally Posted by h4n

This is the one I use:

http://www.amazon.com/HM-Digital-TDS...ords=TDS+meter

$20 shipped, works fine for me! And i know plently of people on here who use the same thing.

EDIT: that one I linked does have ATC, it just doesnt say no the decription. As most amazon item decription are vague. It actually say it on the box in comes in.

Definitely picking this up, thanks! Thanks to GeToChKn for the advice on the ATC too!

[AaronMB]

Originally Posted by cprash

Definitely picking this up, thanks!

+1.