My mg depletion rate is 100ppm. Is it possible?

[Coleus]

I have no sand bed and this is not a new tank. It used to be FOWLR tank and then switch to reef tank.

I top up about 15 gallon of RO FW per week and do 15 gallon of water change every week

[Myka]

100 ppm per week is definitely high, but not totally unreasonable. I go through 40-50 ppm per week, but my Acros are all fairly small yet.

[The Grizz]

Originally Posted by Coleus

I have no sand bed and this is not a new tank. It used to be FOWLR tank and then switch to reef tank.

I top up about 15 gallon of RO FW per week and do 15 gallon of water change every week

I have stopped topping up with FW and only use SW it has helped to keep my levels up. I keep my salinity at about 1.025 but top up with water with a salinity at 1.022. I found when I did use FW my levels dropped and it was hard to get them back.

[Myka]

Originally Posted by The Grizz

I have stopped topping up with FW and only use SW it has helped to keep my levels up. I keep my salinity at about 1.025 but top up with water with a salinity at 1.022. I found when I did use FW my levels dropped and it was hard to get them back.

Doesn't your salinity creep up? How do you counteract that effect?

[The Grizz]

Originally Posted by Myka

Doesn't your salinity creep up? How do you counteract that effect?

No for some reason it stays where I want it and I have been doing this on the new tank, my FOWLR and my old 155 since Nov last year.

[mark]

do you supplement your 15g SW to 1400 before changing?

[Coleus]

Originally Posted by mark

do you supplement your 15g SW to 1400 before changing?

Yes I do, I supply 3 tables spoon on my 15g SW and i am using IO reef crystal salt.

[mark]

Originally Posted by Coleus

Yes I do, I supply 3 tables spoon on my 15g SW and i am using IO reef crystal salt.

You just need 3 tbsp of Mg to supplement 15g? Your IO mix must be way higher than mine out of the pail. Highest I seen has been 1100 so using this calculator and MagFlake looking at 5oz for 15g.

[globaldesigns]

Originally Posted by The Grizz

No for some reason it stays where I want it and I have been doing this on the new tank, my FOWLR and my old 155 since Nov last year.

Hmmmm, I also question this process... Water evaporation doesn't remove salt, so if you top up with salt, you would be adding more salt. So I am a little confused that your Salinity doesn't change for the worse.

I would personally not do that, as I think it will eventually catch up to you, quicker than you think. Unless you have some sort of salt monster that eats salt.

[globaldesigns]

In regards to MG, 100ppm in a week can happen, I have seen it on my tank. During times when I see more growth than normally, that is when I use more additives