Water changes

[Redrider]

Help. I’ve been advised by one LFS to use a combination of salt and RO/DI when doing a water change. This morning, in a conversation with the manager at another LFS, I was told to use salt water only at water change and to use RO/DI for topping off only.
This makes sense to me since I’m having trouble maintaining salinity.
My question: What should I be doing at water changes?
I’ve done one water change and did a 14 gallon change(90 gallon tank). 7 of it was salt, 7 buffered RO/DI that was buffered.
I’m either adding too many fish too quickly or something is “off” with my recreation of the eco-system. I lost 3 fire fish in the last 2 weeks, one after the water change, two before.
I tested the water and have had LFS test it. I get the same answer from all. “ Your water is fine”
Thoughts anyone?

 

[James M]

Your lfs is right. During a water change you match the salainity from your tank and replace the water. What is your salainity?
Do you have a auto top off?
How old is your tank ?
How are you acclimating the fish ?

 

[Crabs McJones]

You want to do water changes with saltwater mixed up to the same salinity and temperature as the tank. And RO/DI only for top off.

 

[Shufflepig]

You should top off with RO/DI water. When you do a water change your replacement water should be RO/DI water properly mixed with salt to the same specific gravity as your tank water.

 

[lapin]

Water is fine hahahahahahahahhaa ask the fish if the waters fine.
Do you have a refractometer? If so calibrate it with calibration fluid. Then test your water. You want it to be around 1.025 or 1.026
When you top off you use rodi water. Salt does not evaporate. So to keep the salinity at the same level add rodi (fresh water no salt)
Water changes. You take out salt water so you add salt water to replace it.

 

[lapin]

Now What do you mean by buffered water????

 

[lapin]

As for dead, dying fish. There are many factors as to why fish die.
It could be a fast change in salinity.
When you add fish do you make sure the water they are in matches the salinity and temp of the water in your tank?
Another big factor is alkalinity.
If there is a big change between your tank and the water the fish came in it can shock the fish and they might die.
The last big thing that effects fish is ammonia. Even small amounts. Do you test for it in your tank?

 

[lapin]

Let me add that fish can be sick and not show any signs. Where ever they came from might be using a low level copper to suppress disease. I strongly recommend you read about QT for fish. TTM and 2 doses of Prazi Pro and some MetroPlex can go a long way in ridding new fish of Ich and parasites. You do not want new fish to bring in disease that will kill your all ready healthy established fish.
You asked for comments and Im not shy. *-)

 

[Redrider]

Well.... first question first.
I DO use a calibrated refractometer. As stated, the salinity is low. Im getting 1.020-.22 most of the time. I do not have an ATO. The tank is just 3 months old.
Yes, I acclimate by an accepted method. Yes I test for ammonia. I test or take to a LFS to test Ammonia, nitrites ,nitrates ,total alkalinity, ph, salinity,
My total alkalinity and salinity are always low
I use Kent Superbuffer-dkh to buffer RO/DI and mix 7 gallons at a time. This is for topping off unless I’m trying to raise salinity, in which case, I use Catalina water. I’ve tested this new water and salinity is at 1.025.
After the water change, salinity was 1.022 and Ph at 8.0. It’s a FOWLR but I’d like to try coral eventually.
On the subject of deaths, the response that got my attention was the difference in alkalinity between my water and the water the fish came in.
Doesn’t the acclimation process acclimate the new fish sufficiently in regards to doh or ph?
I believe I do need a QT. I’ve been lucky so far but I know from freshwater experience that it only takes one sick fish to destroy the entire tank.

 

[lapin]

Sounds like you are doing things correctly. Usually fish come in lower salinity water around 1.022. If you are acclimating that should be fine as you are close in salinity and Ph. 14 gallon water change on a 90 should not make too much of a change that might effect fish. Dont know why they have died. Were they all from the same vendor?

 

[Redrider]

The fire fish were from the same vendor but I’ve lost fish from 3 different LFS.
I Just returned from getting more water and having the water tested again. I’m at 0’s on ammonia, nitrite, nitrates. 8.0 on ph and 1.020 salinity.
One LFS suggests getting larger hardy fish. Another seems to be positive I have a predator killing the fire fish. They (she) scoffed at the idea that high MG would affect a swim tank adversely.
I’ll be changing to a 120 gallon rectangular tank and hopefully peddle the 90 gallon.
I won’t be in a hurry to add the next victim or victims.

 

[acabgd]

Basics first - water from your tank will evaporate. Salt will stay behind. This will *increase* salinity. I don't know if you have a sump or not, but there is a place within your tank where you will see that the water level drops within a couple of days. That level should always be the same. You should replace the evaporated water with fresh (RO/DI) water.

Your tank should be running around 1.025 salinity. When doing a water change you need to do that with saltwater. Mix it to 1.025 salinity, take a certain amount of water out of the tank and replace with the same amount of saltwater.

How are you changing the water currently, in detail?

 

[Redrider]

Basics first - water from your tank will evaporate. Salt will stay behind. This will *increase* salinity. I don't know if you have a sump or not, but there is a place within your tank where you will see that the water level drops within a couple of days. That level should always be the same. You should replace the evaporated water with fresh (RO/DI) water.

Your tank should be running around 1.025 salinity. When doing a water change you need to do that with saltwater. Mix it to 1.025 salinity, take a certain amount of water out of the tank and replace with the same amount of saltwater.

How are you changing the water currently, in detail?

Thanks for the detailed answer.
I do have a level marked where I top off. I had been adding RO/DI. My dkh is low as is Ph so I’ve been buffering with Kent super buffer dkh.
Recently, I decided to get the water parameters in line for a reef tank, thinking I was ready for that adventure.
That’s when I tried raising my salinity. Yes, I know the evaporation will raise salinity and the reason why it does so. Therein lies the issue. The readings I get are consistently low. I started topping off with Catalina saltwater from the LFS. I tested it for salinity before using it. It was 1.025 on the refractometer. The refractometer was calibrated and has ATC.
At the last water change, salinity was 1.022. It’s a 90 gallon “L” shaped acrylic. Today, on my refractometer and that at the LFS, I’m at 1.020. This,after topping of exclusively with Catalina saltwater.
The sump has a Magma curve 7, the refugium contains live rock and Chaeto. The return pump is a QO4000, dialed down.
I have been “harvesting” salt that has evaporated on the top and a small accumulation around the sump and put it back in the tank.
I know I’m lacking some detail but I get long winded.

 

[acabgd]

Something's not adding up. If you're topping off with 1.022, there is not a scientific possibility of you having 1.020 after a few days, unless you add too much fresh water.
Also, "harvesting salt" after just a few days also sounds a little crazy. I might have some small salt creep after a month or so, but certainly not in quantity that would make my salinity drop by 0.002.

How much fresh water are you topping up (daily, weekly)? Where do you see the level has dropped? Do you top off manually? How much water do you change and how often? How much do you take out and how much do you put back in?

 

[Redrider]

Something's not adding up. If you're topping off with 1.022, there is not a scientific possibility of you having 1.020 after a few days, unless you add too much fresh water.
Also, "harvesting salt" after just a few days also sounds a little crazy. I might have some small salt creep after a month or so, but certainly not in quantity that would make my salinity drop by 0.002.

How much fresh water are you topping up (daily, weekly)? Where do you see the level has dropped? Do you top off manually? How much water do you change and how often? How much do you take out and how much do you put back in?

Thank you for the response.
Yes, I know things aren’t adding up. That’s why I sought advice from those with more experiences.
I’m researching ideas elsewhere as it seems no one has an answer here. Most if not all your questions have been answered already. Thank you again

 

[Redrider]

Thank you for the response.
Yes, I know things aren’t adding up. That’s why I sought advice from those with more experiences.
I’m researching ideas elsewhere as it seems no one has an answer here. Most if not all your questions have been answered already. Thank you again

Ok, I think I figured out the root cause of my issues.
In an article from another site, I found an explanation of the drain system.
I hope I’m not violating copyrights.
“
Although the hole vent is typically very small, a considerable amount of air is drawn through it. The water and air mixture that travels through the pipe down into the sump mixes together vigorously. The bubbly water dumps into the sump.

When the water exits down in the sump, even more bubbles are created. The bursting bubbles result in salt spray — and salt creep on the surrounding surfaces.”

This morning, I found a large area on the backside of the sump where I couldn’t see well, that had salt deposits. I added some of the salt back in, hopefully not enough to distress fish or the other critters.
I was at 1.019 yesterday. After the salt harvest was added back into the sump. Salinity on the refractometer- 1.020 an hour later.
I believe, the new tank will not have these same issues. The new tank arrives on Monday. I’ve lived with it this long(3months) so I might as well live with it a few more days.
Thanks to all for responding. All responses gave me food for thought and help me to eventually lead to what I hope is the issue.

 

[Captain Quint]

Now What do you mean by buffered water????

Some old school LFS owners will add pH buffer to your RODI fresh.

I don't agree with it because your pH could skyrocket when you do a top off with their water.

 

[lapin]

Since this popped up again. How much does your skimmer remove in water volume per day? Wet skim. How much fresh water are you using to top off each day?

 

[Captain Quint]

@Redrider from what I am inferring you're having difficulty achieving a desired specific gravity. You state your water seems to be a constant 1.020 and yes you are doing as instructed.

I would imagine your evap rate might be perhaps around a gallon a day +/- and you are using the RODI fresh to top off which is the correct thing to do however it would remain at the 1.020 range.

A simple way to slowly increase the level you desire say 1.023 to 1.026 can be done by doing the top off with the salt water of your choice whether it be the Catalina NSW or ASW until you have slowly safely reached where you wish to be and once there cease the top off with the saltwater and resume adding the correct top off using the RODI fresh water. I'm kind of wondering why your LFS did not suggest this to you.

When it comes time to do whatever water percentage you wish to do ensure you remove exactly the gallons you wish and use the ASW or the Catalina NSW at the same salinity level as that which you have achieved to get avoiding the fluxes and shock of drastic swings. Your pH will start to balance as well.

I hope this made sense.

AND, if it were opposite...say you added too much saltwater with a higher range accidentally you could dip out and use RODI fresh to get back to your normal rate.

I hope this helps and it is pretty much what others have suggested just in a simple form. Please keep us advised on your progress because we want to see you enjoy a nice healthy system with happy fishes.

~Best Regards~

 

[Captain Quint]

Since this popped up again. How much does your skimmer remove in water volume per day? Wet skim. How much fresh water are you using to top off each day?

Great point my friend. I top off what is lost in the cup with small amounts of saltwater for the balance.