PWC - How much?

[Charlie]

I have 110lbs of LR and sand in a 46 gal tank. I'm guessing that there isn't more than 40 gals of water in the tank. I'm doing a 5gal PWC weekly. That's about 12% per week; is that sufficient or should I be changing more?

 

[lando]

If your are doing ot on a weekly basis, that should be fine. If it goes longer, bouble the amount. You can get 15-20 gal rubbermaid tubbs for pretty cheap to mix up more water if needed.

 

[Charlie]

I've been mixing water in 5 gal Poland Springs bottles which is easy to carry from the sink into my office. A heavy air stone sits on the bottom nicely and bubbles away for days. Adding dechlorinator and salt, nothing else.

 

[melosu58]

As Lando said if every week you are OK. Weekly are better.

 

[Trameltanz]

Weekly is good. Lando is the man!

 

[tecwzrd]

I've been mixing water in 5 gal Poland Springs bottles which is easy to carry from the sink into my office. A heavy air stone sits on the bottom nicely and bubbles away for days. Adding dechlorinator and salt, nothing else.

Are you checking the ph to make sure it matches the tank before adding? The limited surface agitation in a 5 gal water jug could cause a ph drop after a couple of days. The temp matching isn’t as important since you're doing 12% but I still wouldn’t add without heating if more then a 10 degree difference. Also you’re wasting your money on adding dechlorinator since most salt mixes have it also and the mixing for days would dissipate it anyways. I’d use an uncovered 5 gal bucket instead and cover to transfer if you do have ph issues. A small 2 litter pitcher fits inside to empty it half way and then pouring the other half is pretty easy.

The amount you change is more dependent on your chemical test results more specifically no3. Overstocked/overfed tanks can still suffer greatly with 10%-15% weekly pwc and I’d test your no3 levels weekly and keep it at 20 ppm or less for FOWLR or 5 ppm or less for reef. With larger (i.e. 20+%) PWC temp/sg/ph/alk matching to the tank becomes more critical and even slight variations can cause stress and/or death to your stock.

 

[Charlie]

tecwzrd,

I use the chlorinator to remove chlorimides (sp) which I am told do not dissapate like chlorine does. Not sure on this but that's what I was told. I was originally using PRIME but was told not to use it when a new tank is being cycled/matured.

I did not check the bottled water PH but will in the future. So far the display tank PH has been stable around 8.2.

Regular tank testing reveals undectable amonia, nitrites & nitrates. The tank only had 2 damsels and a hermit crab in it since the initial cycle completion. Two small Perculas and a quarter size red sea star were added yesterday. An army of small snails should be here tomarrow. Light beige algea just appearing on the sand and glass in the last day.

Thanks for your response. All of you have provided me with tremendous insight into this new hobby.