Water Changes: 50% Daily vs 100% every 3 days?

[Dave C]

If you change 50% water daily your WQ factor (whatever that is, just a comparative measure of crap in your water) will end up going from 1.0 after a w/c to 2.0 before the next day's w/c and then back down to 1.0. So on average you'll have a WQ factor of 1.5.

If you change 100% every 2nd day it will go from 0 after to a w/c to 1.0 the next day to 2.0 before the next w/c and then back down to 0. So on average you'll have a WQ factor of 1.0. So if you did only 95% instead of 100% it would be marginally higher then 1.0... it works out to 1.105.

So that would lead you to believe that doing a 95% w/c every 2nd day would be better then a 50% w/c daily. The problem with that conclusion is we don't know what the range of nitrates would/could be. But let's assume that what you're saying is that with a 50% daily w/c your nitrates get as high as 40ppm and then drop to 20ppm after the w/c and then back up to 40ppm the next day. That tells you that your fish are producing 20ppm per day. So with a 50% daily w/c your nitrates range between 20 after a w/c and then back up to 40 before the next day's w/c, averaging 30ppm, but never exceeding 40ppm.

With a 100% w/c every 2nd day your nitrates will range from 0 to 40 with an average of 20ppm. With 95% it works out to a range of 2.1ppm to 42.1ppm with an average of 22.10ppm. So that would tell me that it makes sense to do 95% w/c every 2nd day rather then a daily 50% w/c. The maximum nitrates barely exceed the 40ppm that it does with a daily 50% w/c and the average is lower, and your workload is less.

btw, if you do the same analysis with a 95% w/c every 3rd day your nitrates should range from 0 to 63.16ppm with an average of 33.15ppm. So the average would lead you to believe that you're in the same boat as a daily 50% w/c but the spike to 63ppm could be a problem for your fish.

[Dave C]

btw, that analysis doesn't take into account that your tap water has 7ppm nitrates. After lunch I'll try & figure out what effect that will have on the different w/c cycles.

[White Worm]

Dave that was some good info, I think more impressive is that I understood what you were saying. thanks.

[White Worm]

discus.jpg 47,90EUR = 55, 56$ US?

Contains the following tests:


pH value (pH)
total hardness (GH)
carbonate hardness (KH)
ammonium/ammonia (NH4/NH3)
nitrite (NO2)
nitrate (NO3)
phosphate (PO4)
iron (Fe) and
copper (Cu) or chlorine (Cl)

[CAGE-RATTLER]

Good stuff dave!

Im gonna check out some other nitrate test kits to find one easier to read and hopefully give me some more precise results. When they jump from 10 to 20 to 40 to 80 to 160 ....... it will be very hard to get the precise measurements.

I just finished testing and with this AQ master kit ............ i just scratch my head when testing nitrates. depending how close i hold the vial to the card ......... the color changes quite a bit and with it right against the card ........... im reading 160 which i know cant be right ....... lol.

All other tests with that kit are easy except the nitrate.

Once i get a good kit ........ hopefully tonight .......... im gonna start testing daily and before and after WC's to see what i come up with and put the results on an excel spreadsheet to keep track and post my results.


Do any of the nitrate test kits use something other than color swatches??

Maybe like a pool test kit that has the colors alongside the vial so you can just hold it up to a light to get an accurate reading?

like the one in this pic

http://www.howibuiltmyownpool.com/im...ric1-large.JPG

Hmmmmmmm ......... i wonder if any of the pool test kits have a nitrate test?
Im do for new one for my pool anyway so i'll have to check that out.

[Dave C]

If your water has 7ppm nitrates in it that doesn't really change anything. Assuming your tank/fish are still producing 20ppm of nitrates per day the 95% every 2nd day w/c will still outperform the daily 50% on average. As the daily production of nitrates decreases the difference between the two methods will shrink but the 95% method is still better.

All of these calc'ns ignore the effect that such a large w/c will have on your fish. I store/heat/agitate my w/c water so I don't think it would have a big effect on my fish, but some might run into trouble with such a large change of water.

[CAGE-RATTLER]

All of these calc'ns ignore the effect that such a large w/c will have on your fish. I store/heat/agitate my w/c water so I don't think it would have a big effect on my fish, but some might run into trouble with such a large change of water.

Another good reason for doing them every other day or every 3rd day as it lets the water age longer.

At the present i only store enough for a 95% wc a day and that will depreciate more as i add new tanks.

[CAGE-RATTLER]

I just found this test kit made by hanna instruments that looks to be more accurate and with the see thru windows like on pool testers.

Any one know what that amount is in US Dollars?

http://www.hannainst.co.uk/acatalog/..._test_kit.html


edit: nevermind ..... only shipping in the UK.

[CAGE-RATTLER]

Just found it here from a east coast distributor.

http://www.bestlabdeals.com/ProductD...t1140&CartID=1

Lil expensive but may be worth it for more accurate tests.

ooops looks like its a $50 minimum order policy but look like free shipping.

Anyone else interested in one? lol

[White Worm]

Cage..you gotta lot of time on your hands doncha? I would use some of that time on enjoyment instead of constant worrying and daily testing and tracking JMO. This is fun, I sit and watch them sometimes for .......well....lets just say I watch em alot. I dont once think, oh i have to check their nitrates, I just say...wow nice fish and very friendly....and always hungry. i would rather watch them for slight symptoms than spend numerous hours looking at viles and trying to match swatch colors. If your fish are thriving and healthy, dont change a bunch of things and dont start doing experiments. This is when inexperience leads to trouble for you and ME TOO. Sometimes very good is good enough. I'm not saying for moment that you should never try new things but small steps and less worry. Its kinda like having a gauge or a light in your car that measures engine temp. If you have a light, you never worry until the light comes on. If you have a gauge, you are always looking at it to make sure things are good (too much tests + too much info = too much worry sometimes). Either way, your car might over heat but you either enjoyed the drive with nice scenery or you missed it all because you were always looking down at the gauge. Once in a while, glance at your light and make sure its still good. Hope you understood my analogy. Sorry for hi jacking your thread.

[candyl70]

Hey Cage.... instead of doing a 50%, then two or three more small ones to get rid of poop etc, why not let the poo sit there, and then do a larger w/c, say a 75% w/c a day. Do you have enough room to store the water? If not, you should invest in getting a large trash can and storing water in one of those as well. Esp. if you are planning on more tanks later. Just some suggestions!


Candy


LOL Mikey!!! Nicely done!

[Dave C]

At the risk of being crapped upon, how about just not overfeeding the fish? Then you might be able to change less water less often.

[gators111]

The other way to keep nitrates from climbing so quickly is to keep your pH under 6.5. At that pH, ammonia is ammonium and IME my tanks stay under 5ppm of nitrate doing once a week 85% water changes. I believe the ammonium doesn't convert as quickly as ammonia, but I could be way off on this.

[candyl70]

[Kindredspirit]

Cage..you gotta lot of time on your hands doncha? I would use some of that time on enjoyment instead of constant worrying and daily testing and tracking JMO. This is fun, I sit and watch them sometimes for .......well....lets just say I watch em alot. I dont once think, oh i have to check their nitrates, I just say...wow nice fish and very friendly....and always hungry. i would rather watch them for slight symptoms than spend numerous hours looking at viles and trying to match swatch colors. If your fish are thriving and healthy, dont change a bunch of things and dont start doing experiments. This is when inexperience leads to trouble for you and ME TOO. Sometimes very good is good enough. I'm not saying for moment that you should never try new things but small steps and less worry. Its kinda like having a gauge or a light in your car that measures engine temp. If you have a light, you never worry until the light comes on. If you have a gauge, you are always looking at it to make sure things are good (too much tests + too much info = too much worry sometimes). Either way, your car might over heat but you either enjoyed the drive with nice scenery or you missed it all because you were always looking down at the gauge. Once in a while, glance at your light and make sure its still good. Hope you understood my analogy. Sorry for hi jacking your thread.

LOL!!!!! ya think?? That was hilarious~




Marie~