Is there a maximum you can do on a water change? - Other than completely draining the tank

[Tpeck]

[I would first identify the problem...see if it’s the water or the lighting system. If you do a massive water change and the source of the problem is not addressed it’s just an exercise in futility. It also adds/puts lots of stress on the tank inhabitant’s just viewing pleasure....IMHO]

 

[dvups1]

[This person has to identify the problem first. If There is nothing wrong with a big water change like that to get the ball rolling (so to speak) if he is battling a phosphate soaked reef. If the problem is bad lighiting or over feeding however, he is wasting money and time because a water change won't help the lighting and if he continues his current feeding cycle he will nulify the water change.
High nitrate and phosphate are usually the culprit but you have to determin why they are high. If not, you'll just be on the tail end trying to keep up with the water changes.]

 

[Kitty]

[Those are good thoughts, and I thought I would add mine the other way, just in case....

I had to do a 50% water change when my tank crashed from AMMONIA. Quite a different problem than hair algae, but it saved my fishies. I took out the water from the bottom, by using a pump, so the worst stuff was taken out. Then added the new water SLOWLY, like three hours, to fill up the 140 tank. Just like a new acclimation, I had to make sure the water temp was the same, the salinity, etc.

It CAN be done, but certainly not recommended!

There are fish / inverts that eat hair algae. If your friend can stand a few more snails, I highly recommend getting some Turbos in there!

And of course, as mentioned, finding the cause of the algae is really important! Where I am, high phosphates - even in my RO/DI water - is a problem. I use Phosban most of the time, or the white pads that remove all the bad things in the water. (Sorry, can't remember the brand name - someone will pop up with that, I'm sure!)]

 

[kwl1763]

[While large water changes can be done (if done correctly matching pH, temp, salinity, etc.) but I'm afraid this will help him little or none in the long term!

There is a nutrient problem fueling the algea growth either from the rock, sand, water, overfeeding, weak skimming, whatever but unless he has high nitrates and/or phosphates the water change won't help much.

Echoing others, If he does have high nitrates and/or phosphates a big will change will help with the parameters short term but long term the cause has to be found or it will be a never ending battle!]

 

[Jacob]

@kitty32 wrote:

[Poly filters, by Poly Bio Marine.]

 

[grim-bob]

[Has he done any testing of his water?

What are his parameters?
ammonia
nitrite
nitrate
phosphate
calc
alk

Getting these would be a good starting point. A large water change can be done to help as long as you are very careful about matching the major paremeters as Keith mentioned above. But as everyone else mentioned it most likely won't cure the problem long term. Gotta find the source. Good luck.]

 

[mwolek]

[As long as your careful to match the salinity and tempature of the new RO/DI water, it shouldn't be a problem.]

 

[dvups1]

[

By "bad lighting" I am refering to bulbs that have shifted their output spectrum.

The first step in battling GHA is to start with current tank parameters and log them somewhere to chart progress. The general rule of thumb for tank parameters are as follows:

Temp 76-84 degrees ( this swing should be kept to a minimum 76-78 or 78-80 or 82-84 for example )
Calcium 400-450 ppm
Nitrite 0 ppm
Ammonia 0 ppm
Nitrate 0 ppm
pH 8.0-8.3
phosphate 0 ppm

These values will vary but you should strive for stable and consistant levels.
So many thing can attribute to water quality going south that once you have a your readings on your water's chemistry you have to decide what and how you want to try and affect the particular reading.
For example, if your nitrate reading is above 5 ppm you know it is high but the reason for the high reading has to be determined. Do you use RO/DI water for top off and water changes? Do you have too many fish for your current system to handle? Do you feed the few fish you have too much food or too often? Is there enough water movement through your liverock to maximize bio-activity to aid in denitrification? Is your skimmer efficeint enough for your bio-load? Has your DSB (if your running one) ehausted its critters that allow for denitrification?
It can be a long process but as others have stated you can't start until you know where you are.
Post everthing you can think of in reguards to this particular tank and I know the problem can be found and fixed. It didn't get in the shape it is in overnight so it won't be fixed overnight as well. However, it can be fixed. :beer:]

 

[melev]

[Here's the article about GHA:

http://www.melevsreef.com/gha.html

Maybe it will help your friend isolate some of the issues that are causing this problem. David (bulldogger1)'s advice is excellent, and he knows what he's talking about.]

 

[Jacob]

[It will be easier to help if you quantify, "off the chart high". What number is that?]

 

[melev]

@66deuce wrote:

[Typically, NO3 and PO4 will be 'bound up' in the algae, and give false readings in the tests. You have to reduce the volume of algae first, then the tests will become more accurate.]

 

[melev]

[Yes, that will yield more accurate results.]

 

[dvups1]

[Ok, here is the deal. Your striving for 0 nitrate and 0 phosphate so that there is no fuel to feed your hair algea. Although your posted test results are not very specific, I can tell you that since you are getting a phosphate reading and a nitrate reading you need to beef up your clean up crew to handle the algea you have and double up on your water changing routine. Make sure you test your new top off water and your new saltwater for phophates. So many people make the wrong assumption. They think just because they purchase fresh water from a LFS, the water is perfect. Sadly, this is not always the truth. You could very well be feeding your problem with what you think is the cure.]