Normal Water Change Amount

[jellyfish4me]

I'm sorry I keep asking so many questions and thank you in advance for taking the time to help.

My tank is new and cycling with live rock. The rock has been in there for less than a week. This is a 5.6 gal fluval spec V tank. It has a small overflow section with a return pump on one side of the tank (built-in). This side was where the filter sponge was supposed to go. I have removed it and keep my aquarium heater and some rock rubble in there.

I did my first water change today. I took enough water out to drain the overflow section almost. But I did not take enough water that it run my pump dry. And I would like to keep it that way.

I measured the removed water when I was done and it was approx 55 oz... There are 128 oz in a gallon, so lets say I removed 1/2 a gallon. (I will take a little more next time to get it up to the half gallon mark).

My question... How often should I do a water change then under normal circumstances? The tank has a 2.5" sandbed and about 12 lbs live rock. There has to be less than 5 gallons of total water?

I can easily do a water change twice a week if I need to get a gallon changed a week, but am wondering if the half gallon a week will be enough?

By the way... My ammonia level tested at 0.50 ppm before and after the the water change. It's just a cheap API test kit from Petco where I have to add drops to a test tube with tank water, shake and compare color to a card. I'm not sure how accurate it is.

[dyazdani]

One-half gallon is ~10% so you should be fine with that for routine weekly changes. You don't have to do it every week, but I find it a nice frequency plus in my case, I don't do protein skimming, etc so it helps to keep my water quality high. The API tests are OK for cycling.

[jellyfish4me]

I don't have a skimmer either. There is just not enough room for one. But I'm going to skip adding fish and only add shrimp. So I'm hoping my water doesn't get to bad. But I do like to feed my aquapets! I think I'm just going to stick with this 1/2 gallon weekly and I can always change to a twice-a-week water change if I notice any tank measurements getting out of wack.

I was just thinking it was supposed to be 20% a week, but it has been years since I was in this hobby and I also never had a tank this small.

Thanks for your help :)

[dyazdani]

A general rule is 20-25% a month. Since it is easy and cheap with a nano, I do more than that. Are you getting corals with the shrimp?

[jellyfish4me]

yes. I want soft easy corals. Some mushrooms, green star polyps, ect. and my favorite pulsing xenia. I know some people think the xenia is a weed, but I can stare it it for hours. I love it.

[moe458]

the problems with xenia is that it can spread like a weed but if you keep an eye on things it should be fine..i started with one colony and now i have 4 and this i'm talking within 4-6 months.

[jimnchal]

You should let the tank cycle before doing anymore water changes.

[jellyfish4me]

I don't change any water during the cycle? I did not know that. I thought I was supposed to do some water changed to preserve some of the critters on the rocks. It has feather dusters, starfish, pods, ect. (Even a few aptasia, but that's another post)

[kmbyrnes]

I've had my 12 gal nano running since August. I usually do a 2 gal water change every week. It's easy and helps keep the water clean, since I have no skimmer.
I just turn off the pumps for the few minutes it takes to drain and re-add the water.