Cycling Process

[CStrickland]

Yeah, more I read, more complex the cycle appears to be with lots of factors to consider!
I just topped my sand bed up to about the same now, about 1.5-2".
I called the fish shop I purchased the live rock from and they said phosphate level in their tank was less than 0.25ppm...so I have no idea where its coming from. Maybe the aragonite?

You want to aim for .03ppm phos, that's the ocean average so it's a good goal for a tank. The shop might be using one of the cheaper tests like API that only read down to .25ppm. I have a Hanna checker ulr that I find accurate, easy to use, and relatively inexpensive.

Phosphate is really important to all kinds of life. Algae likes it for basically the same reason as all critters do. Living things use phosphate as a sort of "currency" to save and spend energy. More here https://en.m.wikipedia.org/wiki/Adenosine_triphosphate

Phosphate can "bind" to other things like carbon, this is called organic phosphate. It can also be free, inorganic. When algae grows it is taking up the free/inorganic phos from the water. When something dies and rots, it's bound/organic phosphate is freed into the water. When we feed the tank, organic phos is added, fish and corals eat it, then poop alot of it out (digestion is pretty inefficient) but keep some bound in their body, then bacteria work on unbinding it from the leftover food and poop releasing free phos into the water. This phos stays in the water until it's bound by the carbon in our rocks and sand, or algae, or gfo, or LC, or whatever skimmers are pulling from the water. Our tests can only see the free phos, not the bound stuff (you have to like dissolve the rock with acid or something for that).

I'm not sure anybody knows for sure how exactly phos gets released from our carbonate sand and rocks. Some say bacteria messily pull it out for their biological processes if they can't find an easier source, some say phos travels from high to low concentrations because it desires an equilibrium, some probably have other theories. In any case, when you put phosy rock in phos-less water, the phos comes out. That's bad if the phos-less water is your fish tank and you don't like algae, and high phos is thought to inhibit coral growth too.

But I bet a lot of the phos you're seeing now is released from the dead stuff on your rock, the same stuff that's giving you ammonia. It's all decaying and releasing those building blocks of its life. Other life will use those building blocks - bacteria as you cycle, algae, diatoms, etc. and the rocks and sand will soak up some phos too if they have room for it.

 

[leviburns89]

+1

Our rock has the surface area of a football field per Sq inch. So it has the potential to hold insane amounts of dead organics.

When you cure rock, you are basically letting all this dead matter decay to a point where the biproduct (phosphate) isn't an issue. This can potentially take months. Depending on the amount of dead matter in that batch

 

[robertsk]

had a question on cycling, dropped in 2 shrimps to decompose in my tank 3 days ago(live sand, cured live rock). Today did all the tests, was just wondering if i should do anything or let it sit like that?

salinity 1.021
ph 8.1
alkalinity 6
phosphates below 0.03
ammonia 1.2
nitrites 0.2
nitrates 5.5

also should i do a wc while tank is cycling?

 

[kcinnick]

had a question on cycling, dropped in 2 shrimps to decompose in my tank 3 days ago(live sand, cured live rock). Today did all the tests, was just wondering if i should do anything or let it sit like that?

salinity 1.021
ph 8.1
alkalinity 6
phosphates below 0.03
ammonia 1.2
nitrites 0.2
nitrates 5.5

also should i do a wc while tank is cycling?

You can remove the dead shrimp, the process has started.

The water column has very little bacteria in it, almost none.

All of the bacteria is clinging to Rocks, Sand, filter media, sides of the tank, whatever. It doesn't just float around, doing a water change at this point isn't really effective and wasting money.

 

[gikseiman]

Yea that's way high. I'd run GFO to pull that down or you'll have a crazy algae bloom.

Yes, was beginning to see algae bloom.

I changed about 20% water and phosphate level almost halved.

I actually have GFO (Aquavitro phosfiltrum) in one of the back chambers, but I don't think it is being very effectively.

I tried to put it so water flowed through it, but maybe I need to get a media reactor or something and attach to return pump so water is forced through the reactor?!

Anyone tried this and is it worth it?

 

[gikseiman]

I would dose lanthanum chloride before I started using gfo.

If your levels are that high, you could burn thru $100's in gfo before you see results.

Lanthanum binds the phosphate insantly, you just have to be careful how you use it.

There are a bunch of topics about it.

I'll have a closer read of lanthanum chloride, haven't come across that one yet! lol So much reading :uhoh3: hahah