Newbie, confused about nitrates

[Fishinwall]

Randy Holmes-Farley

After another 18 gal
Diluted: 20 ppm
Straight: 80 ppm

Sure wish my tank was 20.

 

[Randy Holmes-Farley]

What percentage of the water volume is that 18 gallons?

 

[Fishinwall]

I think about 25%. I have a 65 gal plus 30 sump which is about half full... Minus rock etc, I think I have about 70-75 gal.

 

[Randy Holmes-Farley]

Ok, so hopefully after a couple more you'll see it moving down significantly.

 

[Fishinwall]

I sure hope so. Almost have another 18 gal ready just mixing and getting it up to temp. Should be ready in an hour.

 

[Fishinwall]

After the fifth change... Still at 80.

My brown dioms are starting to turn into green patches of algae, should I be concerned?

 

[Randy Holmes-Farley]

After the fifth change... Still at 80.

My brown dioms are starting to turn into green patches of algae, should I be concerned?

I don't know if that is any concern. You may be running out of silicate for the diatoms, which is typical unless you add it somehow.

 

[Fishinwall]

What is silicate?

I decided to do a 36 gal water change. I got a bigger container.... I'm losing patients with the multiple water changes at this much water every time... I'm hoping one last big one can get me to the 10% weekly maintenance changes.

 

[Randy Holmes-Farley]

Silicate is a chemical in seawater that diatoms use to make their internal "skeletons". When silicate runs out, diatoms cannot continue to grow.

I discuss it here:

Feature Article: Silica In Reef Aquariums ? Advanced Aquarist | Aquarist Magazine and Blog

 

[Fishinwall]

Well a 44 gal brute Is NOT 44 gal! 37, 38 tops!

 

[Randy Holmes-Farley]

It might be less than 44 gallons, since they say that is "nominal" just like a 2 x 4 isn't 2" x 4", but how did you figure it to be low?

 

[Fishinwall]

I've been using an 18 gal container that I had measured out using a gal milk jug... I but two 18 gal of water into the brute and it was about half an inch from the top.

 

[Randy Holmes-Farley]

I've been using an 18 gal container that I had measured out using a gal milk jug... I but two 18 gal of water into the brute and it was about half an inch from the top.

OK, but the 1 gallon milk jugs may hold more than 1 gallon when totally full.

For example, a 2 L soda bottle contains something like 2.1 L of fluid when full to the top.

 

[Fishinwall]

Ok well. Either way I just changed a ton of water! Done
So how long should I wait before retesting the water for nitrates?
Randy Homes-Farley

 

[Randy Holmes-Farley]

As soon as the new water is fully mixed with the old, it is suitable for testing. I expect that's less than 5 minutes in a sumpless tank and might be an hour or more in a system like mine with extended sumps and refugia.

 

[Fishinwall]

Ok I just have a sump underneath. I'm going to give it 45 min, then I'm going to test. You think that should be good enough?

When I was changing the water, I stuck my head in the display tank....sure smelled like a crabby ocean.

 

[Randy Holmes-Farley]

Sounds reasonable. Think of it like adding food coloring. As soon as the tank is one shade of color, its mixed.

With the smell, as you trying to suck up detritus, and so may be stirring things up, or just removing water?

 

[Fishinwall]

I really didn't stir much up but there was one small area, about four inches x four inches that I rubbed down a bit to get the brown off.

Water is almost clear already. I'm a bit anxious to try it, if you can't tell.

 

[Fishinwall]

The detritus would only be from the one crab I have in there....been in there about four to five weeks... But you know I've been doing water changes like crazy.

 

[Fishinwall]

Sounds reasonable. ?

Randy I have an aluminum screen that I made to keep my fish in the tank (if I ever get any in there lol)... Is it ok if the aluminum momentarily touches the water until the system hits it's rhythm and balances out...water level drops in main display?