Water change - maximum % of water to change out?

[scubafrogman]

When doing a water change what is the maximum percentage of water that one would remove from an aquarium?

I'm battling an algae problem in a 29G Biocube (approx. 20G of water volume). I usually do a 5 gallon water change (25%) but was wondering if it would be safe to do a 10 gallon (50%) water change?

 

Temp. = 78.1

SG = 1.025

PH = 8.1

Ammonia, Nitrite, & Nitrate = 0

I don't have a phospate or Alk test kit. I added a fish the other day and it died in one day yet my (2) clowns, bicolor dottyback, and cleaner shrimp are all fine.

 

Also, how long should snails last? I bought a cleaner pack from reef cleaners back in Sept. 2014 and they almost all seem to have perished.

Thanks!

[paulrw]

as long as the temp,salinity,ph. etc. all match you can do 100% water change. but probably better to do a few smaller changes over the course of a couple days.

 

some folks here with small tanks 1-3g or so put the whole tank in a sink and add what ever the tank will hold in new water and just let the water over flow over the top to completely flush out the tank.

[IThas2Bme]

You still count the water in the back chambers if you are talking total water volume. It is good to be aware of the display area for stocking purposes. Some people do a 50% WC every six months, some more frequent than that. The key is to match all parameters as close as possible for big amounts like that if you have sensitive corals/ inverts.

 

You can fight the algae but you'll have better results if you solve what is feeding it. Hold old is your tank?

[scubafrogman]

I set my tank up on 9/1/2014 with (2) Eshopps foam sponges and Seachem Matrix in the back chamber. On 1/1/2015 I removed the foam sponges and Matrix and replaced with a Tunze 9001 and an inTank media basket with Purigen and Chemi-pure Elite.

This was probably a mistake as this is when I started having real algae issues. I took out some of the rocks and scrubed them and flushed with RO water. This helped some but the hair algae keeps coming back on the sand bed and rocks.

 

I only feed my fish once a day. I was giving them about 1/4 of a frozen brine shrimp cube thawed in tank water. I tried switching to flakes thinking that I was adding phosphates with the frozen food but it doesn't seem to be making a difference.

[B16acrx1988]

Cut feeding, and run some phos pad or a media bag with gfo in one of your chambers. I just swapped to a new tank and found out how awesome a hydrogen peroxide scrub was on my live rock, so that might be an option I your hair algae is that bad.

[Azedenkae]

I set my tank up on 9/1/2014 with (2) Eshopps foam sponges and Seachem Matrix in the back chamber. On 1/1/2015 I removed the foam sponges and Matrix and replaced with a Tunze 9001 and an inTank media basket with Purigen and Chemi-pure Elite.

 

This was probably a mistake as this is when I started having real algae issues. I took out some of the rocks and scrubed them and flushed with RO water. This helped some but the hair algae keeps coming back on the sand bed and rocks.

 

I only feed my fish once a day. I was giving them about 1/4 of a frozen brine shrimp cube thawed in tank water. I tried switching to flakes thinking that I was adding phosphates with the frozen food but it doesn't seem to be making a difference.

Your feeding is fine, you are going to add phosphates regardless. It is a problem with your filtration, not your feeding. For reference I feed my fish 2-5 times a day.

 

What needs to be done is to find a way to clean up excess nutrients. There are various filter media that helps. I tend to prefer biological ones, as they can run indefinitely.

 

As for water changes, 10-20% is my usual amount every few days.

[smeagol108]

astrea snails do a great job on hair algae, but it wont solve the root of the problem.

[scubafrogman]

I have chemi-pure elite, purigen, and phosguard in my media basket and was doing a 5 gallon weekly water change. Nothing stops the green hair algae and green snot algae from returning.

I do need some more snails as all mine have seen to have died.

[CronicReefer]

When you removed your biofilter media all at once like that you probably created a nutrient spike causing the GHA to take off. You need to find out your phosphate levels as well. Turbo snails eat GHA pretty well but you need to solve the nutrient issue. Phosphate adsorbers sometimes need to be replaced more often than what is recommended. I also think GFO or ExtraxPhos are better products to use than phosgaurd. I would get rid of the purigen and just stick with the chemipure and a phosphate adsorber.