How often should i change water?

[scbwdt]

Hello. I have a question about water change.
I have 30g 1.010sg tank with two juvenile puffer which is about 1 inch or less.
My tank has built-in bioball filter and also running two canister filter rated for 125G & 40G.
Ammonia and Nitrite stays 0 and Nitrate is about 10 or less.
I usually change water 50% once a week and cost of $alt is killing me ~_~
It's been almost two week since last water change and i want to know if its necessary to change water so often.
My puffers seems happy and healthy so i guess water is pretty clean.
I need a advice from expert.

[bertie 83]

50% weekly is generally essential. If you up the sg and go full marine you can cut back on waterchanges.

[RVS]

I don't fully remember, but i think was PP who told me that skimmers start to work on 1.018 or above.
So, if your puffer species allow 1.018, you should go there and instal a Skimmer that will save you from salt co$t.

[scpion]

My guess is that u have a pair of figure 8, so going full marine may not be an option. its always mention that overfiltration is recommended by imo, having the 3 filters running is an overkill coz there is limit to what they can remove. The filter is there to hold physical waste and house bacterial for ammonia and no2. They do not take out no3 and many other nutrients. i bet if u were to remove the filter rated for 125g, u might still have the good readings. Unless U upgrade to a much bigger tank, water changes weekly is still a must to remove the excess nutrients.

[nzac]

in most cases, in a not overstocked tank it is possible to do biweekly waterchanges instead of weekly. Not the reccomended or best idea but as long as your nitrates are still under 20ppm the fish are not suffering any ill effects.

[trekenk]

My guess is that u have a pair of figure 8, so going full marine may not be an option.

Nope they have two GSP so going full marine is an option. Take it up to full marine with the proper saltwater fliteration of live rock 1 1/2 - 2 lbs per gallon a good skimmer and plenty of flow and you can cut your water changes to about once a month. That is with a tank upgrade of at least 60 gallons while your at it.

[bertie 83]

I assumed gsp as salinity is at 1.010. The tank upgrade is a must tho

[hadla]

in most cases, in a not overstocked tank it is possible to do biweekly waterchanges instead of weekly. Not the reccomended or best idea but as long as your nitrates are still under 20ppm the fish are not suffering any ill effects.

so is a single f8 in a 20g understocked? just curious cause figgy is by herself.

[J-P]

what kind of puffers are they?

The search function on the forum still is not working.

[nzac]

I don't consider any tank understocked, there is a huge difference between properly stocked and overstocked though, and I certainly would not consider 1 F8 in a 20 gallon overstocked.
I set my own water change schedules by nitrate levels in each individual tank. I have 13 tanks running 2 get weekly waterchanges, the rest get biweekly. Usually by waterchange day the nitrate levels are between 10-20ppm.

I do agree 50% weekly is very good advice, obviously it is not what I live by, but very good advice nonetheless.

[bertie 83]

I just believe 50% weekly is safest to start. I do more cos I want to lol ocd

[J-P]

You SHOULD weekly.

The volume that you take out varies on the bioload of the tank.

[RTR]

+1 to J-P's comments.