Should I do a 100% water change?

[SolarReefer]

Hello all, i recently added a diamond goby and now my nitrates are testing 75 on my Hanna checker. Would you recommend a 100% water change or a 3 30% water changers over a period of 3 weeks?

 

[Pachiman]

What size is the tank? And did it just spiked from out of nowhere or you didn't test it before?

Doing a water change won't fix the nitrate issue, we need more information like current bioload, what filtration are you using, how old is the system. You have to know how the nitrates went so high in the first place.

Lets just assume it is a small nano tank brand new and this is your first fish and you just cycled it - do 4, 25% water changes in 2 weeks. If you do a 100% water change you will probably kill or stress out the fishes.

 

[vetteguy53081]

Hello all, i recently added a diamond goby and now my nitrates are testing 75 on my Hanna checker. Would you recommend a 100% water change or a 3 30% water changers over a period of 3 weeks?

Doing a Water change WILL lower the nitrates as will addition of ChemiPure elite to sump
I recommend 25-30% water change and then do 3 gallon water changes over the next 7 days. As soon as tomorrow, take a water sample to a store that does NOT use Api kits and have them test your ammonia and nitrates and compare readings- then you'll know where your levels truly are at and to confirm your readings

 

[brandon429]

Randy’s article specifically says water changes won’t help (rebounds quickly due to location source not changed) I’d consider its alternate offers:

Aquarium Chemistry: Nitrate in the Reef Aquarium

This article provides background on nitrate in the ocean and in aquaria, and describes a number of techniques that aquarists have successfully used to keep nitrate levels down to more natural levels in reef aquaria.

reefs.com

also, make sure you’re sand is cleaned. The fish can eat pellets, he’s not existing on sandbed waste it’s just something they sift through looking for bugs

It does no good to battle nitrates while simultaneous storing them up as sandbed waste.

 

[SolarReefer]

Randy’s article specifically says water changes won’t help (rebounds quickly due to location source not changed) I’d consider its alternate offers:

Aquarium Chemistry: Nitrate in the Reef Aquarium

This article provides background on nitrate in the ocean and in aquaria, and describes a number of techniques that aquarists have successfully used to keep nitrate levels down to more natural levels in reef aquaria.

reefs.com

also, make sure you’re sand is cleaned. The fish can eat pellets, he’s not existing on sandbed waste it’s just something they sift through looking for bugs

It does no good to battle nitrates while simultaneous storing them up as sandbed waste.

So would you recommend I siphon the entire sand bed then do some larger water changes? I’ve hardly touched my sand in about 6 months since setting the tank up. I was under the impression the sand bed held a lot of beneficial bacteria so I didn’t want to disturb it a lot. But 75ppm nitrates is really high. My corals are stressed, some are dying and I’ve lost 2 fish so far.

 

[anthonymckay]

Randy’s article specifically says water changes won’t help (rebounds quickly due to location source not changed) I’d consider its alternate offers:

Aquarium Chemistry: Nitrate in the Reef Aquarium

This article provides background on nitrate in the ocean and in aquaria, and describes a number of techniques that aquarists have successfully used to keep nitrate levels down to more natural levels in reef aquaria.

reefs.com

also, make sure you’re sand is cleaned. The fish can eat pellets, he’s not existing on sandbed waste it’s just something they sift through looking for bugs

It does no good to battle nitrates while simultaneous storing them up as sandbed waste.

That's a 20 year old article talking about keeping nitrates < 1ppm, and describes 0.9ppm as "elevated nitrate levels". Water changes do indeed make THAT goal difficult. But that's also a VERY outdated goal by most standards today. Multiple large water changes will certainly be able to have an impact on lowering nitrates from 75ppm.

 

[brandon429]

And then they rebound right back up in a few days. The science hadn’t changed

the sinking of a sandbed will do it

not changing the fish load and keeping the same inputs for feed will do it

not having plant loading will do it

changing nothing about the current production will cause the rebound

also factors: just because a level is stated for nitrate doesn’t make it correct. These levels stated are guesses, they may be at 10 ppm or 120 ppm= see nitrate test kit comparison threads to note the readings can range 100 ppm difference between kits. This is all horse shoe guessing.

We would need a new article to replace that one as faulty before we discounted the stated article, the actions of nitrate haven’t changed at all in twenty years

 

[brandon429]

@SolarReefer

thats not the cause of any of your issues, nitrate isn’t harmful. Paul B and several reefers here run 160 ppm at times.
fish disease from skipping preps is your likely fish issue


corals can be managed to stay alive, make changes other than to nitrate. I wouldn’t mess with your sandbed right now, it’s not the cause of anything. Was just stating that to own one while chasing nitrate is counter productive

there are unspoken variables in your coral challenge, for example we don’t know if you’re running gfo where phosphate uptake is the issue, or perhaps you’re too bright and white on your lighting and it’s bleaching them

or alk may be off, or feeding...don’t factor nitrate at all in your hunt it’s not burning or harming anything at all.

what if all white rocks and no live rock are starving the corals

post a pic of your tank for starters we can begin helping

 

[Randy Holmes-Farley Verified Community Expert]

That's a 20 year old article talking about keeping nitrates < 1ppm, and describes 0.9ppm as "elevated nitrate levels". Water changes do indeed make THAT goal difficult. But that's also a VERY outdated goal by most standards today. Multiple large water changes will certainly be able to have an impact on lowering nitrates from 75ppm.

lol

I try to not be outdated, but do not let the date, or any misinterpretations reefers make based on it, cloud reality.

I have never said that water changes do not work to lower nitrate. Obviously they do and I have many articles that detail EXACTLY what they accomplish (see graph below).

Here's what I said, EXACTLY:

"Note that I don’t include any discussion of water changes, though obviously they work to some extent. The problem is that it is very hard to reduce the nitrate concentration to natural levels in that fashion unless the system is constantly flushed with clean water."

It is certainly true that multiple rapid large water changes will reduce nitrate to whatever goal you want. I show that in the graphs below (Figure 1). But what they will not do is keep nitrate at that level unless you keep doing those same changes (Figures 8 and 12)

Water Changes in Reef Aquaria by Randy Holmes-Farley - Reefkeeping.com

Figure 1. Nitrate concentration as a function of time when performing water changes of 0% (no changes), 7.5%, 15% and 30% of the total volume each month. In this example, nitrate is present at 100 ppm at the start, and is not added or depleted during the course of the year except via the water changes. The y-axis can alternatively be thought of as the percent of the original concentration remaining for any material that is not being added or depleted from the water except via the water change.

Figure 8. Nitrate concentration as a function of time when performing daily water changes equivalent to 0% (no changes), 7.5%, 15% and 30% of the total volume each month (in other words, 0%, 0.25%, 0.5% and 1% per day). In this example, nitrate is present at 0 ppm at the start, and is accumulated at a rate of 0.1 ppm per day when no water is changed.

Figure 12. Nitrate concentration as a function of time when performing daily water changes equivalent to 0% (no changes), 7.5%, 15% and 30% of the total volume each month (in other words, 0%, 0.25%, 0.5% and 1% per day). In this example, nitrate is present at 100 ppm at the start, and is accumulated at a rate of 0.1 ppm per day when no water is changed.

 

[V A R I A N T]

I think it will be difficult to help @SolarReefer until they share more information about their setup and practices. From what I read from their other posts is that this is a 6 month old 30g AIO running on RODI filtered well water. That’s the extent of the known details. And that there’s likely a dead shrimp in the AIO sump section

 

[anthonymckay]

Appreciate the clarification on this Randy, thank you

 

[SolarReefer]

What size is the tank? And did it just spiked from out of nowhere or you didn't test it before?

Doing a water change won't fix the nitrate issue, we need more information like current bioload, what filtration are you using, how old is the system. You have to know how the nitrates went so high in the first place.

Lets just assume it is a small nano tank brand new and this is your first fish and you just cycled it - do 4, 25% water changes in 2 weeks. If you do a 100% water change you will probably kill or stress out the fishes.

This is a 30 gallon tank that is 6 months old. Already cycled added corals yaddayadda. Now I’m getting a diatom bloom on my sandbed. I recently got a Hanna nitrate checker and it’s the first time I tested my tank for nitrates since the cycle. Tested 70 ppm. I blamed the addition of the goby for the high nitrate level though. Now my goby is nowhere to be found and my nitrates are maxing out my Hanna checker at 75ppm. Here is a picture of the sand bed in the tank

 

[srobertb]

What other fish do you have? What are your nitrates “normally?” What is your salinity and temperature. TDS of your outgoing ro/di water?

tested for ammonia or nitrites?

I’ve run a perfectly clean (looking) reef with corals and fish at 60ppm. I’m not sure 75ppm (while high) is what’s killing your world.

 

[SolarReefer]

I think it will be difficult to help @SolarReefer until they share more information about their setup and practices. From what I read from their other posts is that this is a 6 month old 30g AIO running on RODI filtered well water. That’s the extent of the known details. And that there’s likely a dead shrimp in the AIO sump section

I think it will be difficult to help @SolarReefer until they share more information about their setup and practices. From what I read from their other posts is that this is a 6 month old 30g AIO running on RODI filtered well water. That’s the extent of the known details. And that there’s likely a dead shrimp in the AIO sump section

This reply made me laugh haha. You are correct 6 month old aio with a most likely dead shrimp and now very possibly a dead goby. Haven’t seen him in a few days. 30 gallon tank running carbon and chemi clean in a media basket, skimmer and filter media. Here are my most recent parameters.

 

[SolarReefer]

What other fish do you have? What are your nitrates “normally?” What is your salinity and temperature. TDS of your outgoing ro/di water?

tested for ammonia or nitrites?

I’ve run a perfectly clean (looking) reef with corals and fish at 60ppm. I’m not sure 75ppm (while high) is what’s killing your world.

Very interesting. Yeah I’m really trying to get to the bottom of it. Hoping it’s not my well water. It comes out at nearly 700 tds out of the tap so I know my rodi system is working overtime but my tds meter always reads 1tds on line 3. I have 2 clowns a fire fish and a cleaner shrimp as well as a CUC. Recently had a royal gramma, tomini tang and diamond goby die. Pulled all of them out immediately other than the goby. He’s just disappeared.

 

[MoshJosh]

TLDR. . . yes big water changes will reduce nitrates short term, but will not fix an underlying issue.

 

[V A R I A N T]

What method did you use to cycle your tank? Did you perform a water change after cycling?

Fishless cycling usually relates to high nitrates post cycle and the first water change is important when not employing other methods to reduce nitrate.

 

[fish farmer]

Very interesting. Yeah I’m really trying to get to the bottom of it. Hoping it’s not my well water. It comes out at nearly 700 tds out of the tap so I know my rodi system is working overtime but my tds meter always reads 1tds on line 3. I have 2 clowns a fire fish and a cleaner shrimp as well as a CUC. Recently had a royal gramma, tomini tang and diamond goby die. Pulled all of them out immediately other than the goby. He’s just disappeared.

IMO...six fish in a 30 gallon is your "problem" with high nutrient load. What were your nitrates and phosphates before you added the additional 3 fish?

Either cut back fish load or up your waste management.

 

[SolarReefer]

This reply made me laugh haha. You are correct 6 month old aio with a most likely dead shrimp and now very possibly a dead goby. Haven’t seen him in a few days. 30 gallon tank running carbon and chemi clean in a media basket, skimmer and filter media. Here are my most recent parameters.

What method did you use to cycle your tank? Did you perform a water change after cycling?

Fishless cycling usually relates to high nitrates post cycle and the first water change is important when not employing other methods to reduce nitrate.

I did do a fish less cycle. Cycles with microbaxter 7 & ghost fed. I did about a 40% water change after the cycle.

 

[SolarReefer]

IMO...six fish in a 30 gallon is your "problem" with high nutrient load. What were your nitrates and phosphates before you added the additional 3 fish?

Either cut back fish load or up your waste management.

Yeah I only have 3 fish now. Don’t plan on adding anything anytime soon.