How can I fix percipitation

jordanrb · Sunday at 9:36 AM

I dose 12ml of AFR into my 20g cube. I do it at once every morning. Could splitting my dose in two (morning and night) prevent the buildup I am getting at the lid?

From my understanding adding calcium or alkalinity too quickly can cause it as well as an imbalance with low magnesium. Since my magnesium is stable at 1350-1400 I am going to say that wouldn't be the case.

My temp is stable at 76° so I dont think that would be the cause.

My perameters are:

Calcium 450ppm
Alkalinity 8.2 dkh
Magnesium 1350ppm
Salinity 1.025

Uncle99 · Sunday at 9:39 AM

Less dose volume and more frequent is always better.

If you have a Doser, why not 1ml every 2 hours.

If no Doser, twice is better than once, three is better…and so on….but the volume dosed needs to be very accurate.

Randy Holmes-Farley · Sunday at 11:39 AM

AFR does not cause calcium carbonate precipitate at appropriate doses to maintain alk, regardless of timing of doses.

Where exactly is this precipitation? Lid of what?

jordanrb · Sunday at 2:55 PM

Randy Holmes-Farley said:
AFR does not cause calcium carbonate precipitate at appropriate doses to maintain alk, regardless of timing of doses.

Where exactly is this precipitation? Lid of what?

It is only at the front glass face where the lid meets the glass.

I have never had it before until about 2-3 weeks ago. I can take a pic tomorrow when it builds back up. I wipe it every other day.

56longroof · Sunday at 3:04 PM

jordanrb said:
It is only at the front glass face where the lid meets the glass.

I have never had it before until about 2-3 weeks ago. I can take a pic tomorrow when it builds back up. I wipe it every other day.

You sure that's not salt creep?

Randy Holmes-Farley · Sunday at 6:10 PM

I agree it sounds more like salt creep: a place where tank water dries out and leaves a crust.

jordanrb · 2026-09-28T18:51:33-0400

Randy Holmes-Farley said:
I agree it sounds more like salt creep: a place where tank water dries out and leaves a crust.

I have not changed anything in regards to tank setup so not sure why I would only experience this now.

My salinity is stable since day one. Could there be something else causing it?

Randy Holmes-Farley · 2026-09-28T18:59:00-0400

jordanrb said:
I have not changed anything in regards to tank setup so not sure why I would only experience this now.

My salinity is stable since day one. Could there be something else causing it?

Salt creep won’t cause a noticeable change in salinity.

These deposits are outside the water, on surfaces exposed to air but near the water? Popping bubbles can launch seawater that dries and deposits.

mcarroll · 2026-09-28T20:27:20-0400

Agreed with other comments and questions....also I wonder if water circulation is poor at the surface and/or where the dosing is happening?

jordanrb · 2026-09-28T21:35:54-0400

mcarroll said:
Agreed with other comments and questions....also I wonder if water circulation is poor at the surface and/or where the dosing is happening?

Dont think I want to do too much more circulation in this 20g.

jordanrb · 2026-09-28T21:37:32-0400

Randy Holmes-Farley said:
Salt creep won’t cause a noticeable change in salinity.

These deposits are outside the water, on surfaces exposed to air but near the water? Popping bubbles can launch seawater that dries and deposits.

Sorry I meant I havnt changed anything in the tank like pumps, power heads and such.

Is there a reason why I would be getting salt deposits forming now after 8 months of running the tank the same way?

mcarroll · 2026-09-29T02:10:05-0400

jordanrb said:
Dont think I want to do too much more circulation in this 20g.

Can you post a pic of the deposits or where they form?

Are you aware of "salt creep" and is that what you are seeing?

jordanrb · 2026-09-29T15:48:32-0400

mcarroll said:
Can you post a pic of the deposits or where they form?

Are you aware of "salt creep" and is that what you are seeing?

It seems to be salt creep. I did not know about it until Randy brought it up. Weird that I've never experienced it until now.

mcarroll · 2026-09-29T16:30:13-0400

jordanrb said:
It seems to be salt creep. I did not know about it until Randy brought it up. Weird that I've never experienced it until now.

It takes time.

Wait a few more months and you might be able to notice tiny crystals of salt creep on flat surfaces around the tank....maybe even in other parts of the house.

Saltwater is MESSY. Salt is (oddly as it sounds) sticky and oily, in addition to being able to "creep" around growing crystals.

I've seen pics of saltcreep that grew from a sump, along a power cord, and into a power outlet. That's bad.

Make sure you clean up your tank area regularly. :)