# How much prime do you add?



## Fish rookie (May 21, 2012)

If you have a 100 gallon tank and you are doing a 50% water change, when adding prime directly to your tank, do you add prime according to the dosage required for 50 gallon or 100 gallon?


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## Diztrbd1 (Apr 21, 2010)

you would add the correct amount for the amout of water you are adding.....if you are adding 50 gal of water then treat for 50 gallons. This is how I do it in my 75 and have had no problems, treat the water as your adding it.


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## jobber (May 14, 2010)

If you read the directions carefully, it says 1 capful for each 50 gallons of NEW water.

"Directions*Use 1 capful (5 mL) for each 200 L (50 gallons*) of new water*. This removes approximately 1 mg/L ammonia, 4 mg/L chloramine, or 5 mg/L ......"
Reference: Seachem. Prime


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## Fish rookie (May 21, 2012)

That is what I thought, too... but when re-reading it today it appears to me they suggest to dose by aquarium volume if added directly to aquarium, which would mean to dose for 100 gallon even if I am only changing 50 gallon of water in a 100 gallon...am i missing something here?

Use 1 capful (5 mL) for each 200 L (50 gallons*) of new water. This removes approximately 1 mg/L ammonia, 4 mg/L chloramine, or 5 mg/L chlorine. For smaller doses, please note each cap thread is approx. 1 mL. May be added to aquarium directly, but better if added to new water first. *If adding directly to aquarium, base dose on aquarium volume. *Sulfur odor is normal. For exceptionally high chloramine concentrations, a double dose may be used safely. To detoxify nitrite in an emergency, up to 5 times normal dose may be used. If temperature is > 30 °C (86 °F) and chlorine or ammonia levels are low, use a half dose.


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## jobber (May 14, 2010)

You're missing nothing. It can't get any more simpler than: *Use 1 capful (5 mL) for each 200 L (50 gallons*) of new water.*


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## Fish rookie (May 21, 2012)

Sounds to me like they are saying if you are changing 50 gallon of water in a 100 gallon tank you should dose 2 caps full if you are adding prime directly to your tank; but if you are adding to the new water you dose 1 cap full.

Here is the full instruction for your reference:

Use 1 capful (5 mL) for each 200 L (50 gallons*) of new water. This removes approximately 1 mg/L ammonia, 4 mg/L chloramine, or 5 mg/L chlorine. For smaller doses, please note each cap thread is approx. 1 mL. May be added to aquarium directly, but better if added to new water first. *If adding directly to aquarium, base dose on aquarium volume*. Sulfur odor is normal. For exceptionally high chloramine concentrations, a double dose may be used safely. To detoxify nitrite in an emergency, up to 5 times normal dose may be used. If temperature is > 30 °C (86 °F) and chlorine or ammonia levels are low, use a half dose.


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## Diztrbd1 (Apr 21, 2010)

adding 50% of new water to a tank is going to dilute/ weaken the strength of anything harmful to begin with. You really do not need to add more then the recommended dose for the amount of water being added. I usually add a lil bigger dose but no need to double the dose imo


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## Fish rookie (May 21, 2012)

Thanks John. This is what I thought, too.
I am confused because after reading the instruction I am just thinking if using a hose to fill the tank most likely prime is added directly to the tank--not the new water; in which case, shouldn't the dosage be based on the total volume of the aqaurium as per the instruction? If that is true, then the proper dosage per Seachem's recommendation is 2 caps full of prime--instead of 1 cap full--when changing only 50 gallon of water with prime added directly to the aquarium.
Thank you.


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## Diztrbd1 (Apr 21, 2010)

I don't personally use Prime, but the stuff (Kordon Nov-Aqua Plus) I use doesn't suggest/specify to double up like that and I don't have any problems. You can do it if you feel safer about it, but I personally don't think it's necessary. When I do 40 gal w/c's on my 75, I just add it to the water flowing in... lil bit at a time as it's filling. Usually I do the same with the buffers at that time.


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## Vman (Jan 20, 2011)

You're ok with double dozing it. You can't really over do it by adding an extra small amount. On my 75 gallon I add 2 capfuls with my buffer mix inside. Then gradually add all of it as I'm filling the tank.


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## target (Apr 21, 2010)

For my 90g I'd use one cap full with a WC of around 50g. No need to treat for 100g when you are only adding 50g of new water. I'd start my python refilling the tank, then just dump the whole cap full in at one time and let the tank fill. Never had any problems.


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## Mferko (Jun 8, 2010)

fish rookie read correctly, when adding water directly to tank it clearly says to base dose on entire tank volume.
that being said, the doses on the bottle are just guidelines, chlorine/chloramine levels vary depending on how close you are to the source, if you wanted to be 100% certain you were adding the right amount you would use a chlorine test kit on your tap water and calculate what you need. 
better to dose slightly over than under IMO.


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## Fish rookie (May 21, 2012)

Diztrbd1 said:


> adding 50% of new water to a tank is going to dilute/ weaken the strength of anything harmful to begin with. You really do not need to add more then the recommended dose for the amount of water being added. I usually add a lil bigger dose but no need to double the dose imo


I suspect the concern is more about the amount of chlorine added to the tank with the new water, rather than anything harmful that are already in the tank.
I am not sure if I am adding more than the recommended does since in the case of adding prime directly to the tank, isn't the recommended dose one which is based on full tank volume--that is, 2 caps being the recommended dose and 1 cap being half the recommended dose?


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## Foxtail (Mar 14, 2012)

Prime also neutralises ammonia, but I am guessing that if you are filling from the tap they say to dose for the entire amount of the tank because when you fill the tank the new water doesn't just stay on top it mixes and the chlorine spreads out throughout the tank. So you would dose for the entire amount. 

Sent from my Galaxy Nexus using Tapatalk 2


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## Mferko (Jun 8, 2010)

yea it said on another forum too that some will be used up detoxifying heavy metals in the tap water and that were released by the fish waste, some detoxifying any ammonia/nitrite both in the tank and in your tap water (its higher from the tap in spring when theres lots of runoff), and also it said chemical reactions are somewhat chance based in that the molecules need to "collide" in order to react, more prime > more collisions > faster reaction > less chlorine killing bacteria

its safe to double the dose so i don't know why anybody would use a 50% dose unless they had already established chlorine levels in their tap water are very low

at work so not going to waste time finding that other post but im sure you can find the information on google


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## Fish rookie (May 21, 2012)

I used to think you only add the amount replaced when doing water change regardless of where and how you add your prime. However, after giving it some thought and reading the replies here, my opinion has changed.

My understanding is that when adding to new water you can only add the amount required for the volume of the new water because you only need to dechlorinate/detoxify that amount of water to make sure no chlorine/ammonia/heavy metal... enter your tank; when you add to the whole tank the prime is diluted by the whole aquarium and your new water is mixed with the old water so you need to make sure the whole tank is dosed in order to have the same effect.

Having said that our chlorine level out of the tap is not high and there is no nitrate/nitrite/chloriamine in our tap. so for many people it is probably fine to does 50% of the recommended dose, whether they know they are actually dosing only 50% or not. 

Nevertheless, according to the instruction, the proper way to do it is to dose the whole tank--not just the amount replaced--when adding directly to the tank. The proper dose may vary depending on condition of tap water so a full dosage for one person may be the half for another, but the point remains that a full dosage for the whole tank is recommended even when you are only changing part of your tank water--when adding prime to the tank directly. 

For example, for a 50% waterchange, if you feel that your chlorine level is low and you want to use 1 cap as a full dosage for a 100 gallon rather than 50 gallon that may be fine, but if you are adding prime to your new water you only need to use 1/2 cap while if you are adding to your tank you should add 1 cap full.


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## bonsai dave (Apr 21, 2010)

sodium thiosulfate is one of the main ingredients in Prime and when used too much can be harmful to fish. I would get a chlorine test kit and test your water to see how much chlorine is in the water. Andrew So's discus truth book has a good write about sodium thiosulfate .


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## April (Apr 21, 2010)

I just do a sploosh. We don't have much chlorine. No need to measure. Add a capful if you want to measure. Don't overly concern yourself too much about chlorine remover. 
April who has never measured. ; )


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## seanyuki (Apr 22, 2010)

You switched to seachem prime iso sodium thiosulfate .....why?


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## seanyuki (Apr 22, 2010)

HTH ......TOO MUCH PRIME WITH WATER CHANGES! - Page 6 83 and Larry Bugg's NADA ex President and a long time discus keeper.

For what it is worth, I heard back from my contact at Seachem. Here is his reply. Pretty much what has already been stated by a lot of people here.

Hey Larry,

Sorry I am just getting back to you, I have been out of the office at a show. We are very happy to sponsor such events and I am gladd that it was a success. Just wish I could have made it, especially for the auction!

To address the dosing of water conditioners, we must first look at how they function. All water dechlor or conditioners function by employing a reducing agent. This compound reduces and binds with assorted molecules to render them harmless. In the case of chlorine, a reducing agent will break the bond between the two atoms resulting in two chloride atoms. The same happens with chloramine only this results in three chloride atoms and a nitrogen. Most conditioners, especially Prime and Safe, also bind with other compounds to render them harmless. Ammonia, nitrite, and nitrate are just a few of the common compounds that are effected. So, when you add Prime to a solution containing ammonia, nitrite, nitrate, and chlorine, some of the Prime will break apart the chlorine and some will bind with the other compounds. So, if you are doing a water change in a tank that contains a fair amount of nitrate or some other compound, some of the conditioner will be utilized to detoxify these and will not be available to break apart the chlorine or chloramine. If you treat the water before adding it to the aquarium, the conditioner will remove any of the chlorine and chloramine. Any remaining conditioner will then bind with other compounds when added to the tank.

So... if adding water to the tank before treating, it is best to treat for the volume of the entire aquarium. This ensures that there is enough of the conditioner available to remove any chlorine or chloramine, without being effected by any ammonia, nitrite, or nitrate currently in the water. Think of it this way, when treating water before adding it to the tank, there are less harmful compounds to be detoxified. When adding it to the tank first, the conditioner will have more than just chlorine and chloramine to detoxify and therefore will require a larger dose. With Prime and Safe being as concentrated as they are, this typically requires little product but, is a great way to ensure your fish are safe.

Hope this helps, let me know if you have any additional questions or need me to clarify anything.

Larry Bugg
NADA BOD Member
2012 NADA Convention and Show - Atlanta, Ga.
Sponsored by - Southeast Discus Enthusiast

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## Fish rookie (May 21, 2012)

Thank you Francis, Dave, April, John, Mferko, and everyone else for your help.

Just to clarify I am not going to put discus in this tank, it is for something else. Since I have never had such a big tank before and I just dont seem to have any luck with the tap these days yet I cannot age that much water I am wondering what is the proper amount of prime to add during water change. 

Originally I just assume it is very 'simple' and to just dose the amount of water replaced but then I read the full instruction carefully and realized it is not quite as 'simple' as the first sentence of the instruction may imply so I thought I should ask. Thank you for all the reply.

And I especially appreciate and want to thank the reply from Seachem that Francis so kindly pasted here for all to read, and learn.

I will keep using only sodium thiosulphate for my discus tank. Actually since I do not see any air bubbles on the glass after a water change and I also cannot smell any chlorine from the barrel before I pour the water in I do not think I have much chlorine, if at all, in my aged water. I tested it with a swimming pool chlorine kit and the reading is below the minimum on the chart. Just to be safe I still add a few sodium thiosulphate crystals in the tank.

Yes, I think I have read about the overdose of sodium thiosulphate from Andrew Soh. I think he said he lost tens of thousands of dollars from overdosing. It hurts the gills or something like that, right? 

I will be very careful that I do not overdose. What will the discus do if they are overdosed? Anything I should watch out for, please?

The recommended dosage on the package is 1 crystal for 5 gallon but I am actually only adding 1 crystal for every 10 gallon right now.

Once again, thanks a lot for everyone's help. This is such a wonderful community with so many knowledgable members willing to share their knowledga and experience. It is awesome!


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## mikebike (Sep 8, 2010)

I have been adding the correct amount of the dechlorinator/Prime/AquaPlus for the amount of water I'm replacing.

When I am doing water changes via garden hose I add the conditioner directly into the flow of the water going into the tank.

I have had no problems with this way of doing things.


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## Fish rookie (May 21, 2012)

Thanks for the link, I did not see this thread onsimply and it is a looonnnnnnnnnnnnnngggggggggggggg thread..LOL 6 pages is just unbelivable. I did nto read pastthe first page, thanks for copy-and-paste the last page.

Sounds like most people on simpy discus have been treating the whole tank when doing water change with prime.

I have read that because in Malaysia there is no chloramine they use only sodium thiosulphate and not prime or any commerical dechlorinator, while in Singapore they have chloramine so they need more than just sodium thiosulphate.

I have never done this experiment myself but apparently sodium thiosulphate will turn the color of PP purple so by adding PP it is found that sodium thiosulphate only stays in the aquarium for about 24 hours? In other words, if you add sodium thiosulphate in your tank today, and then add some new water (untreated) tomorrow or the day after without any dechlorinator the chlorine in your new water will not get neutralized by the dechlorinator you added more than a day earlier.

Out of curiousity, do you use prime or just sodium thiosulphate in yoru discus tank, please?



seanyuki said:


> HTH ......TOO MUCH PRIME WITH WATER CHANGES! - Page 6 83 and Larry Bugg's NADA ex President and a long time discus keeper.
> 
> For what it is worth, I heard back from my contact at Seachem. Here is his reply. Pretty much what has already been stated by a lot of people here.
> 
> ...


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## seanyuki (Apr 22, 2010)

I am using Seachem Safe for six years without a problem for the discus tank.......dose/treat the whole tank.

hth



Fish rookie said:


> Thanks for the link, I did not see this thread onsimply and it is a looonnnnnnnnnnnnnngggggggggggggg thread..LOL 6 pages is just unbelivable. I did nto read pastthe first page, thanks for copy-and-paste the last page.
> 
> Sounds like most people on simpy discus have been treating the whole tank when doing water change with prime.
> 
> ...


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## Fish rookie (May 21, 2012)

Thanks Francis. Your discus are really beautiful.
Are you using aged water or tap water if you don't mind me asking?
Thanks.


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## seanyuki (Apr 22, 2010)

Over a month and no problems using water direct from the tap also split the discus in two groups......7 discus in each tank.
pics taken last weekend.

     



Fish rookie said:


> Thanks Francis. Your discus are really beautiful.
> Are you using aged water or tap water if you don't mind me asking?
> Thanks.


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