# Top ups?



## BBXB (Oct 7, 2012)

Just wondering when you top up, do you just use straight RO water or remineralize the RO water to match tank before pouring in?


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## shrimpzoo (Jan 15, 2012)

BBXB said:


> Just wondering when you top up, do you just use straight RO water or remineralize the RO water to match tank before pouring in?


Top off with straight RO water.

Top off is to replace the water that has evaporated from your tank.

If you remineralize the RO water to match the tank before pouring it in you are going to keep bumping up gH and kH overtime and kill everything when it hits an insane level.

gH and kH will not leave the water through evaporation, only through water changes.

Therefore:

Top off = RO Water
Water change = Remineralized RO Water


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## BBXB (Oct 7, 2012)

Thanks for the great explaination.

So does TDS increase as well if I used remineralized water to top up? Let's say, my current tank is tds 300 and I top up with water at tds 150, will this increase or decrease tds?


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## randy (Jan 29, 2012)

BBXB said:


> Thanks for the great explaination.
> 
> So does TDS increase as well if I used remineralized water to top up? Let's say, my current tank is tds 300 and I top up with water at tds 150, will this increase or decrease tds?


It's a trick question ;-)
If you TDS is 300, you use TDS 150 water to top off, your TDS will decrease. However, next time when the same amount of water has vaporized, your TDS will be higher than 300.

So it will decrease the TDS short term but will increase long term.


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## shrimpzoo (Jan 15, 2012)

randy said:


> It's a trick question ;-)
> If you TDS is 300, you use TDS 150 water to top off, your TDS will decrease. However, next time when the same amount of water has vaporized, your TDS will be higher than 300.
> 
> So it will decrease the TDS short term but will increase long term.


Yep, think of it in terms of volume and concentration


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## Shrimp Daddy (Mar 30, 2013)

shrimpzoo said:


> Top off with straight RO water.
> 
> Rain water is much better.


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## shrimpzoo (Jan 15, 2012)

Shrimp Daddy said:


> shrimpzoo said:
> 
> 
> > Top off with straight RO water.
> ...


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## Symplicity (Oct 14, 2011)

Top off with pure RO will swing TDS, as others mentioned it is like watering down the tank. Always do slow top-offs and w/c.


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## Fishfur (Mar 4, 2012)

Oddly enough, when I was speaking to Frank at his store the first time I visited, he mentioned that he uses rainwater. His can't be any worse than the stuff that falls in good 'ol Mississauga.


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## randy (Jan 29, 2012)

Frank uses rainwater and has good results, so does a few others I know of. For me I just don't have the energy to collect and move rain water to my basement, so I just use RO. Turn on the faucet and I get it. 

Only thing is that it generates lots of "waste water" that's perfect for other things and shouldn't be wasted. So I modify the waste water tube to my sink and collect those to water the lawn and plants, flushing toilet, washing dishes, ... etc.


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## Symplicity (Oct 14, 2011)

randy said:


> Frank uses rainwater and has good results, so does a few others I know of. For me I just don't have the energy to collect and move rain water to my basement, so I just use RO. Turn on the faucet and I get it.
> 
> Only thing is that it generates lots of "waste water" that's perfect for other things and shouldn't be wasted. So I modify the waste water tube to my sink and collect those to water the lawn and plants, flushing toilet, washing dishes, ... etc.


Thats a genius idea! I will def try to re-use this water for other thinks. Maybe use it for my guppy tank.


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