Water Changes - EP 1: Saltwater Aquarium Maintenance

So why do a water change in the first place? The most obvious reason is to remove some of the nutrients and contaminates that can irritate fish and corals as well as feed algae growth. By doing a water change, we can dilute the concentration of these elements by adding new saltwater.

Now, what is the perfect schedule for water changes? Well, that totally depends on your tank and the inhabitants in your tank as well as the additives and foods you use. It also depends on the equipment you have in your reef aquarium as well - an extremely efficient protein skimmer, large refugium and an intense filter sock cleaning will determine how often and how much of a water change to do. The best answer is to ask people you trust, see how you reef tank reacts to the changes you do and determine what you have time for - smaller water changes more frequently or larger changes spread out over a month. Generally:

15% Once a week (We think is close to ideal)
30% -35% Every other week (What Ryan does :) )
50% Once a month (Acceptable if you are experienced at making sure the new saltwater is the exact same salinity, alkalinity and temp as the tank water.)

Let us know in the comments below what works best for your lifestyle and your reef tank.

Finally, always add the Salt to Water (this prevents precipitation) and try a digital refractometer to test salinity - it may just change life.

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[jakecarpenter]

Awesome great video! I love how you are able to go through the differences in salts, while staying objective. You do something not many people know how to do. You know how to keep with a critically thinking mind. Its non argumentative and antagonizing. Rare skill set to have. Keep up the great work!

[BigLungzMusic]

I like to significantly over filter my tanks and I change 25% weekly an 50% monthly, cleaning my filter every other month. I run a 525 gph canister with uv sterilizer on my 37 gallon reef. Instant ocean salt. The more time and effort you put into your tank, the more beauty you will get out of it

[letsfish]

Smart man I bitxh evry 2 days about changing water I got 30 tanks and still want one more a salt water tank but it’s hard with no help just me

[sethtwilliamson]

Great video as usual.

I do an automated 2% (total system volume) daily using peristaltic pumps plus some from periodic maintenance tasks. That's mathematically equivalent to 15% weekly or 83% monthly.

I have two holding tanks that each hold about a week's worth so I can age the new water a little or use both of them to cover the odd vacation/business trip. A powerhead kicks on to give it a good stir before the change cycle starts. Auto-top-off is powered down during the change.

[rexrodefamily]

This helped me a lot! New to our clown fish tank and fortunately our local aquatic supply store does free water testing! We are experiencing high ammonia in the water and was told to do a 50% water change. That was overwhelming at first but now sounds much more feasible after watching your video! Thanks!!! 🐠

[melindajohnston]

I have a 75 gallon Mixed Reef Tank and I use Reef Crystals from IO.  I do a 14 gallon water change every week, or 10 days, since that's how much salt water my container can hold!  What I like about this regime is that my tank parameters stay very stable.  I do have an Automatic Top Off System which helps with the salinity.  Thanks for all these great videos!

[jayburris]

reef crystals since the beginning and always had great results and i do a 30% water change the first of every month keep it simple and easy to remember. i have found with mineral mud and a refugium water changes can be done less frequent.

[bfisk]

10 gallons once a week for my 75, but lately I've been doing this twice a week. My corals are loving it :)

[SaltyReefTV]

great vid! here's my water change schedule - 30g tank - 5 gallons every 2-3 weeks. or when new livestock is added. filter socks changed daily. skimmer, bio-pellet reactor, carbon, gfo as needed.

[EWRothbot]

I like Kent Reef Salt. I'm not sure about trace elements, but it has really good stats for the basic three (Ca, Alk, Mg).

[sonia]

I'm currently using Red Sea Pro on my 65 gallon reef tank and my LPS/SPS are doing great

[renman]

I have been doing ~10% water changes every Saturday. I have a 225-gallon tank with a 55-gallon sump. I generally go to 20 gallons of new salt water and occasionally do 30 gallons. I almost always mix the salt on the low side, say; 1.021 to accommodate the increase of salt in the tank over the past week of evaporation. I am by no means an expert at this but have learned a lot from you and others about what is the best route. About 6 months ago I had a huge crash (cyano and algae). It was due to lack of husbandry, nothing else. Got back on the water changes and all is good again. I also don't add any trace elements. My thought being, if they are in the salt water that is exchanged every week, I'm probably giving the tank what it needs. My dKH is 8.5, Salinity is 1.025, Calcium is 420, PO3 is 0.0 but I do have a slightly elevated NO3?
I do plan on getting a Kalkwasser setup in the near future.
I would appreciate any thoughts you have on this process?
Dave

[MarineCritters]

Videos are constantly getting better, good work!

[Captluke]

You guys are great! Long time customer here in Clearwater, Fl

[Migrant]

Thanks Ryan for all these awesome videos, I just started my Saltwater tank getting help from your videos, so far I didn't kill my fishes and corals,
Regarding the water change, maybe looks odd but I enjoy water changing, I prepare my water night before water change day (every Friday) and I do 30% water change every week, my tank looks healthy.

[bjorker]

Awesome video, as a big customer of you guys I've been buying the Red Sea coral salt and have had great results wit it! Thanks so much. Grimm

[IntelDrone]

Thanks for reminding me. I haven't done a water change in about a month and a half.

[dgar]

I have a 135g reef tank. I have a lot of fishes in it to. I do water changes every week of 15g.

[JVS_Tarnished]

i used to use red sea coral proand really liked it but switxched it to reef crystals cause of the price and have the same resukts. You seem to need a little more to get the salinity at 1.025 but corals are doing great.

[kelly_ward]

I have a 55 gallon plus 20 gallon refugium for a total of 75 gallons. I change 5 gallons per week which amounts to a 15 percent change. I'm currently using Instant Ocean Reef Crystals but I have no corals and a minimal tank at the moment. But, all is well.