Powder like substance in sump

[devinereef]

Hey everyone, I have had my 250 litre marine tank for 6 months with some very happy fish and clean up crew thriving in the tank. In my sump I have a powdery substance on my heaters and on the sump floor, does anyone have any idea what it is? Is it dust from the sandbed or is something collecting in the sump? Pic attached. Thanks!

Also not sure why the calcium is low, I have started to supplement Red Sea Calcium but can't see any noticeable increase.

Tank parameters:
PH: 8.25
Calcium: 180
Phosphate: 0 (need to raise to 0.02?)
KH: 8dKH
Magnesium: 1350 to 1500PPM (seems to fluctuate I presume it's just the test kit)
Nitrate: 5 to 10PPM
Nitrite: 0
Ammonia: 0
Salinity: 1.025

Many thanks I have just added in Zoas and they are opening, but I know I need to raise the Phosphate a tiny bit, so I am using NeoPhos.

 

[Saltyreef]

Precipitate.

Do you dose alk and cal together?

Perform a very large water change with new salt water.

Try to siphon out the residue.

 

[devinereef]

Precipitate.

Do you dose alk and cal together?

Perform a very large water change with new salt water.

Try to siphon out the residue.

Thanks, when you say large I’ll do about 20 percent as I woudn’t want to over do it?

Also how do you mean new salt? Do you mean buy new salt, I use standard Red Sea Salt which produces 8.3dKH alk

 

[Saltyreef]

Thanks, when you say large I’ll do about 20 percent as I woudn’t want to over do it?

Also how do you mean new salt? Do you mean buy new salt, I use standard Red Sea Salt which produces 8.3dKH alk

Large meaning close to 100%, you can do this over the course of a few days to not stress the tank out. You didnt mention any corals so the fish and inverts wouldnt mind really.

And no i just meant fresh mixed salt water with the calcium elevated at 400.
Mix and heat the water until its clear and at temp.

what are you using to measure salinity?

 

[devinereef]

Great I’ll do that over some days any ideas what’s caused precipitate? I use a D&D Refractometer. I’m sure the fish and inverts won’t mind but I do have some zoas. I’ll just do it over a few days

 

[I never finish anythi]

What do you use to test calcium?

 

[Sisterlimonpot]

Wait, why are you changing out 100% of the water? Tank inhabitants are happy.

And was it determined that precipitation is the cause?

@devinereef do you dose 2 part? Do you space the dosing out so that they aren't dosed at the same time?

Do you run any sort of mechanical filtration?

It seems that what's collecting at the bottom of your sump can be explained by many things.

Low calcium might suggest precipitation, but even if that were the case, I wouldn't change out more water than you usually do.

First identify the problem and then take steps to remedy the problem.

 

[devinereef]

Hi all good morning, I haven't done anything yet, as I am still weighing up the options and what could have caused it, tank inhabitants are happy I have new corals which are Zoas and are starting to open up. It's time to water change anyway, I do a weekly water change for 10 percent, tank volume is 250 litres including sump. I was thinking just gradually every time I do a water change, doing it from the first part of the sump (where this build up is) so as to remove a little bit of the build up every water change, to be honest it's been like that well before I started dosing calcium. I'm not going to do anything drastic, as everyone in the tank is happy and parameters are steady.

Alkalinity always seems to sit around 7.5 so I dose to bring it up to 8.5 then I add in calcium. I add them in pretty much at the same time, I will space them out from now on. I'm not sure why the alkalinity goes down after dosing. It takes a day or two and it goes down from 8.5 to 8 then 7.5.

I have a ClariSea Roller Filter, TMC Skimmer (which is on but not really doing anything as it's just over skimming, but I've been told to leave it on until it beds in but it hasn't bedded in and its been a good few months). I have a phosphate reactor in there to which is off and not been used, as my phosphate is low anyway, so I actually have dosed a tiny bit of NeoPhos, which seems to have helped the corals.

 

[devinereef]

What do you use to test calcium?

I use NT Labs marine test kit.

 

[Garf]

I use NT Labs marine test kit.

Not familiar with that but are you getting a rediculously low calcium result if you test new fresh saltwater?

 

[devinereef]

Not familiar with that but are you getting a rediculously low calcium result if you test new fresh saltwater?

I have just tested new fresh saltwater and it's the same low reading :/ I wonder why?

 

[Garf]

I have just tested new fresh saltwater and it's the same low reading :/ I wonder why?

LOL.Only 3 possibilities I can think of. Get a Salifert test kit (or something like that). If it still reads low, your salt is rubbish or your salinity is insanely low.

 

[devinereef]

LOL - I'll investigate! Thanks for all the suggestions

 

[devinereef]

Hey all, just an update on this, thankfully it turned out the test kit I was using is giving me incorrect readings. I got a Salfert test kit for Calcium and its showing a nice 415PPM for Calcium. All that worry about nothing!