Phosphate drop in a week?

[Reefin' Alaska]

So reef is really only a few months old and never really tested any other tank like I am this one.

I know the Hanna Phosphate ULR tested has +/- .02 tolerance. But my testing last Sat showed .07 P04, this morning was .03. I don't run GFO or any phosphate reducing media. Don't carbon dose.

I'm not exactly sure how I should be looking at that number or what to take away from that? I really am trying to keep it steady. No cause for concern I would assume?

 

[Dan_P]

So reef is really only a few months old and never really tested any other tank like I am this one.

I know the Hanna Phosphate ULR tested has +/- .02 tolerance. But my testing last Sat showed .07 P04, this morning was .03. I don't run GFO or any phosphate reducing media. Don't carbon dose.

I'm not exactly sure how I should be looking at that number or what to take away from that? I really am trying to keep it steady. No cause for concern I would assume?

Tough to say why it is changing. If you want it higher, adding phosphate might be needed soon.

 

[KrisReef]

The concern is that both of your numbers are very close to zero, and secondly where did the Phosphate go? do you have corals that would be assimilating it, or did it bind to the substrate?

People feed their tanks more to increase it but as @Dan_P mentioned others dose it, routinely to keep the level above zero in tanks where it is quickly used up.

 

[Randy Holmes-Farley Verified Community Expert]

Id just keep monitoring.

 

[nano reef]

Id just keep monitoring.

How slowly should you drop po4? One tank was 0.11 and in days I got down to zero. I added recommended amount no change so added tblspoon more then to 0 so took out 1/2 teaspoon. feed corals havily that night.

I am using brs regular gfo. My other tank was at 0.44 so I I added recommended amount plus I think a tbl spoon more few days later maybe 3 it was at 0.02. Going to check today again to see if it dropped more. Dont want dinos. I guess I should keep neopous around in case!

The directions seem to call for small amount. They say once oyur corals get used to a lower amount you can reduce more so to me that sounds like its a low dose to start with.

It says: to avoid shock to livestock start with 1 tblspoon per 4 gallons. after 4 to 8 weeks the tank would have adjusted to lower po4 and the amount used maybe increased If necessary.

So to me that sounds like a low dose. My tank is used to a low amount but then after 3 months it starts to rise and it was right at 3 months.

I had a lot of new highend zoas added and some have died. I do think I may have moved some up to quickly though because I was runing out of sand bed space until my frag tanks is ready. Other than zoas no adverse effects. Most were highend that suffered too!

Should I changeout about 2 1/2 months and use less then recommended next time?

What else is a good substute for gfo? I dont have any special gear I just put in a bag in the sock and my aio in the rack in back.

last time I tried phosguard it didnt do a thing. Maybe I got a bad batch or something!

I also have nothing for nitrates. They stay around 12 to 15. Last time I tried nopox i got dinos. Is no pox a good tool? I think I added to quickly and to much! Thats was my newbie days! lol

 

[Randy Holmes-Farley Verified Community Expert]

IMO, dropping too low is worse than dropping too fast.

If phosphate is around 0.1 ppm, I would not do anything about it.

If phosphate is around 0.4 ppm, then dropping it to 0.1 ppm should be done over several days, IMO.

 

[tapeworm123]

Please do not use gfo unless your phosphate are high and nitrate is low. Gfo (adv reefer tool) strips the water of phosphate and you want your tank to stay in balance with your nitrate/phosphate (red field ratio) . High nitrate and low phosphate is a way to get Dino,s and other algae take overs. Do you use chaeto refugium if so I’ve noticed that chaeto uses po4 more then no3. Just my two cents

 

[Uncle99]

That flux in phosphate is nothing.
Look for a “trend” over weeks and correct only if continuously increasing or decreasing.

The Hanna is good, but the amount in the water is so little, hard to get a consistent answer, buts it’s close.

 

[Randy Holmes-Farley Verified Community Expert]

Please do not use gfo unless your phosphate are high and nitrate is low. Gfo (adv reefer tool) strips the water of phosphate and you want your tank to stay in balance with your nitrate/phosphate (red field ratio) .

I do not agree that nitrate needs to be low. One can work on lowering phosphate with GFO and nitrate with other means at the same time, such as organic carbon dosing or a denitrator.