Do I really need to buy?

[Myka]

Originally Posted by gobytron

Reefwars, unless you can show me some documentation where all of a sudden water changes have gone from being great for nutrient export to poor to somehow poor, I'll have to chalk it up to your opinion.

I think you guys are both right. I have to kind of agree with Denny, and I kind of agree with you. It's not that water changes are a poor nutrient export, it's just that water changes aren't usually the most effective choice. Water changes for nutrient export in tanks that have a small bioload and are regularly maintained certainly may be the best option. For most reef tanks though, there are often better options - especially if you're using a premium salt brand. This is particularly the case when nutrients have gotten out of hand and you're looking for nutrient export for the purpose of nutrient reduction.

For example, I started doing maintenance on a reef tank with about 750 ppm nitrate and 2.5 ppm phosphate. I'm doing 10% water changes and added a biopellet reactor. We're down to about 500 ppm nitrate now. To further make this point, I recently added some dried out live rock to a tub with RO water. The tub had 100 ppm nitrate and almost 0.5 ppm phosphate. Two 100% water changes later and I have noted ZERO difference in those nutrient numbers. Thankfully I can use RO for this instead of saltwater. If you translate that to the above mentioned tank with 750 ppm nitrate, I could have used 3 buckets of salt to do two 100% water changes and I'd still be at square one. I spend what is equal to 6 buckets of salt on a biopellet reactor and biopellets and I'm leaps and bounds ahead.

On the other hand, my own 50-gallon frag tank at home has a skimmer on it, but no other means of nutrient reduction (no carbon, no GFO, no resins) other than weekly 20% water changes. The tank isn't overstocked, but it's definitely full. The tank is maintained at 2-3 ppm nitrate and 0.08 ppm phosphate which is exactly where I want it.

SO my point is, every situation is different, and a nutrient export program needs to be chosen to fit the needs of that particular tank and also that tank's caretaker.

And here's a 12 year old RHF article to prove you ALL wrong because we knew this shizz a decade ago before we even had voodoo biopellets!
http://www.advancedaquarist.com/2003/8/chemistry

[reefwars]

Well said Myka and I agree on smaller tanks especially Nanos I prefer the very large water changes and often do not go much further than that but your right there are a lot of variables from tank sizes to animals and the old answer of just do lots of water changes isn't always the best answer anymore and doesn't always apply universal to each situation

I hope people reading this don't think I'm against water changes I'm actually all for them just not for the sole purpose of exporting nutrients , the benefits of water changes are certainly much more than that