Page 1 of 2
my hydrometer
Posted: Fri Mar 25, 2011 6:14 pm
by ewa1987
i just did a water change, and i realized that my salinity is measured in PPT...but i know that all the info i read measures the salinity in PPM...is there a different number i should be watching for since my hydrometer is in a different measuerment.
i have figure 8's so i know that the salinity should be below 20ppm
and also is salinity and nitrate the same thing????

Re: my hydrometer
Posted: Fri Mar 25, 2011 6:46 pm
by Blaine
salinity has to do with the salt in the water....Nitrates are toxic by products of the Nitrogen Cycle (Nitrifying and de-nitrifying bacteria turn the Ammonia first into Nitrite, then Nitrates) Nitrates can only be removed reliably thru water changes.
One has nothing to do with the other.
Not sure about the PPT or PPM measurements...I'll have to leave that to someone else...
Re: my hydrometer
Posted: Fri Mar 25, 2011 7:09 pm
by sevenyearnight
I have read that figure 8's need to be no higher than 1.008, so in PPT, that would be no higher than approximately 11 PPT, according to this chart I'm looking at. Between 5-11 PPT.
Hopefully someone can verify this for sure for you.
Re: my hydrometer
Posted: Fri Mar 25, 2011 7:28 pm
by Pufferpunk
What brand of hydrometer is this? Are you sure it's for measuring salinity?
Re: my hydrometer
Posted: Fri Mar 25, 2011 8:39 pm
by ewa1987
it measures for both salinity...which is in PPT on one side and specific gravity on the other....i know that the SG should be btwn 1.005 and 1.008...but i just wanted to know if it matters that the salinity is measured in PPt not PPM
the brand is instant ocean...im debating weather i should just get a digital one that sticks to the tank
Re: my hydrometer
Posted: Fri Mar 25, 2011 10:35 pm
by Pufferpunk
LOL, don't worry yourself & just read the SG side.
Re: my hydrometer
Posted: Fri Mar 25, 2011 11:26 pm
by ewa1987
Okay thanks

Re: my hydrometer
Posted: Sat Mar 26, 2011 8:56 am
by RTR
One of my hot buttons got pushed, so I have to expand a bit.
Nitrate is removed by plants and algae in both FW and SW. In SW it is also removed by facultative anaerobic bacteria deep in the pores of live rock, and even some strict anaerobes in LR. In both SW and FW it also is removed by bacteria in DSB and/or plenums.
In plants and algae, the nitrogen is incorporated into the plant or bacterial mass. In bacteria it may be reduced to nitrogen gas and released into the water to bubble out to the air, or may be incorporated into the bacterial mass.
Most hobby tanks lack the processes for nitrogen removal, but far from all. Some of us use use nitrogen removal or incorporation techniques routinely. It is far from "just" or "only" removed by water changes. In FO (fish-only) tanks in FW or SW, water partials are the standard correction technique for excess nitrate, and nitrate is used as routine indicator for all pollution in such tanks, but an awful lot of hobbyists don;t operate many or any FO tanks. FO tanks maximize upkeep, and are standard for novices. There are a lot of alternate ways to operate hobby tanks.
HTH
Re: my hydrometer
Posted: Sat Mar 26, 2011 11:00 am
by Blaine
hahahaha...hilarious.
I was responding to the question. In a F8 brackish tank there are probably no plants, nor a deep sand bed, nor any LR. So the only way he is going to remove Nitrates is thru water changes. And given the question asked about salinity and Nitrates I would think it is definitely a novice so I geared my answer to helping him directly...not giving alot of info that doesn't help this person.
Re: my hydrometer
Posted: Sat Mar 26, 2011 11:40 am
by Pufferpunk
Nitrates can only be removed reliably thru water changes.
I think it was the "only" part that was misleading. Maybe just not thorough enough, even towards a newbie.
Re: my hydrometer
Posted: Sat Mar 26, 2011 12:09 pm
by Blaine
I realize it was a generalization but for the person who was asking the question, it is the only way he can remove the nitrates. Going on and on about that other stuff doesn't help him...even though it is correct.
Also why I said 'reliably'...since very few hobbyists have their tanks set up where all the Nitrates are removed without water changes.
This was a person in need of some very basic information....
Re: my hydrometer
Posted: Sat Mar 26, 2011 2:51 pm
by sevenyearnight
Thank you for explaining that RTR. I knew some of that, but not nearly in that much detail, and that answers a question I had about anaerobic bacteria in LR.

Re: my hydrometer
Posted: Sun Mar 27, 2011 10:03 am
by RTR
Some of us have operated plenums for F-8s and also veggie filters. Too broad a generalization for novices is part of the biggest issue in the hobby today- it leads directly to unsupportable generalizations which are in fact false, but are taught to newcomers who do not know enough yet to see the errors. That leads directly to mythology.
I have spent my time on the web trying to fight myths and errors. This hobby is in reality science-based. It is not a religion. There is no divinely-revealed wisdom involved. It is fact-based and testable. Over-broad generalizations do much more harm than good if they lead folks who need to be learning instead are told to accept such things as facts. That I will not accept, ever.
Off soap box, return to regular programming.
Re: my hydrometer
Posted: Sun Mar 27, 2011 11:59 am
by Blaine
Too much information too quickly can overwhelm a beginner.
We all know the importance of learning math skills,...but we don`t start cramming calculus down the throats of kindergartners. We teach them the basics and add on to it as they grow.
A beginner does not need all that extra info...he can learn that as he grows into the hobby. And the fact remains that in his case the only way he can remove nitrates is thru water changes. I wasn`t writing a paper on Nitrate removal....I was speaking to an individual in need of assistance.
Not every question needs to be answered with a lecture,...sometimes just answering the question directly and erring on the side of caution is best. There was no possible bad result that could have come from my info and if he stayed in the hobby long enough he would have probably learned the other options.
Your answer, while technically correct, gave him a ton of information, none of which could help him in his situation.
Re: my hydrometer
Posted: Sun Mar 27, 2011 1:07 pm
by sevenyearnight
The information provided may assist others reading the thread.