View Full Version : need help with math with pump for water changes
07-28-2010, 12:42 PM
OK i use a 500 gph pump for my water change.
i leave it on for 15 mins. so i figured that is about 150 gallons or so. for my water change i do use stress coat so what percent
of a water chnage is this??
07-28-2010, 12:45 PM
If you have a 500gph pump (and we assume there is no head/resistance on the pump and you're just using it for a water change), then in 15 minutes 25% of 500 gallons has been removed. So, that would be 125 gallons. If you have a 1,000 gallon pond, that's only a 12% water change. So, you need to leave it on for closer to 25-30 minutes and remove around 200-250 gallons--which would give you a 20-25% water change.
You really don't need to use stress coat every time you do a water change. If you use tap water, you do need to use a dechlorinator (or maybe that's what your stress coat is?).
07-28-2010, 03:56 PM
I have about 400 gallons worth of rain barrels. I use this water to top off my pond, etc. In dry spells like we are in now, I allow tap water to stand in the barrels at least a couple of days before using?????????? I have an old pump that I use for everything around the garden. Sometime I let it run, sometimes I just start the flow and let it cyphon.
07-28-2010, 04:00 PM
As long as the water in your rain barrels hasn't come from roof runoff, that's perfectly fine. Rain coming off the roof tiles usually has all sorts of negative chemicals in it due to the way roof tile is manufactured.
07-28-2010, 04:07 PM
I think Stress Coat used to be just a slime coat water conditioner, now it is a dechlorine/dechloramine blah, blah, blah..... Even the usual dechlors like Amquel & Prime have a slime coat additive in them. The thing that bugs me about Stress Coat is the claim that aloe vera helps with the slime coat? This has however never been scientifically proven. I think it's one of those "feel good" things where it works on us, so if we use it on our fish.......... The slime coat really doesn't need to be helped in a healthy pond with the exception of adding new fish or after some type of medical problem. Salt is probably the best slime coat and stress aid for this situation. That is one reason for not always adding it. If Stress Coat is what works for you, I wont argue it one bit. I am cheap so I go with Prime (http://www.fosterandsmithaquatics.com/product/prod_display.cfm?pcatid=5384)! It does all of the above, but a $40 dollar bottle treats 40,000 gallons. Stress Coat (http://www.fosterandsmithaquatics.com/product/prod_display.cfm?pcatid=5389) only treats <16000 gallons for the same price. When Prime goes on sale , it's like $32.
07-28-2010, 04:21 PM
I think Prime is a terrific product too. And be sure to buy Pond Prime (that Squidhead has linked here) versus the one for aquariums, as it's more concentrated and you get more bang for your buck. Since ponds are much larger than fish tanks, you'd need to use way more of the indoor aquarium one, which is not good on the wallet.
07-28-2010, 04:38 PM
Oh yeah forgot to mention, for your pump, to know how much it pumps per hour. I use a watch with a second hand or stop watch on my cell phone and a 5 gallon bucket. Get a bucket that you know the true volume of. Mine is true 5 gallons when filled about 1/4" from the top. Turn on the pump from the location you use it in your pond. Put the output hose/tubing in your bucket. When the first drop hits the bucket start timing exactly how long it takes to fill, Repeat once or twice to verify. Do the math say it takes 30 seconds to fill the bucket. Say you want to remove 250 gallons. 250/5 = 50 . 50 x 30 seconds = 1500 seconds. 1500 seconds / 60 seconds = 25 minutes. If you use a hose to refill, note your water meters gallons used. Make sure no one is using water inside, wash, showers, dropping the kids off at the pool etc. When you are done refilling check the gallons used to verify.
07-29-2010, 12:36 PM
ok thanks all and yes the stress coat is also a dechlorinator it says it right on the lable
07-29-2010, 03:23 PM
then feel free to continue to use it if it works for you and you feel good about the fish. As long as there is a dechlor in it you are solid.
07-29-2010, 07:38 PM
it says it removes chlonie from tap water so the fish are happy and growing fast
Powered by vBulletin® Version 4.1.10 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.