Have not done a water change in almost 2 months



Active Member
View Badges
Feb 19, 2020
Reaction score
PO4 is probably the most unforgiving parameter. 1 is about 8x the upper limit of 0.12ppm.

we missed a key number. NO3 Nitrate

I know you posted 0. but my guess with the other numbers you posted you are using the API test kit. It can give you a false zero for NO3. That is why we recommend better test kits for NO3 and PO4.

So no panic yet, since you may not be at 0 N03.

zeros can lead to cyano and worse dino outbreaks. So we need to get a reliable NO3 reading fast,

We can assume that NO3 is at best low and PO4 high. You many need to run some GFO to get the PO4 number down. But we'll need to thread the needle here. Bringing up Nitrates while bringing down phosphates without triggering a cyano or dino outbreak.

You don't have coral or macro alage to help here, so yes, start using gfo but go slow and don't go below 0.12 yet. We dont want to over shoot nor drop too fast so test daily.

You should have nitrate if you are feeding your fish, so I suspect that the dirt in the sand bed is using it up but not enough to use up the PO4.
Thanks Champ.

I agree that the API tests are terrible. I do think that I will have SOME Nitrate in the system. Doing the test again I think it is not 0 and it may well possibly be 0.25 or 0.5, just too hard to tell with the colour. I also want to add in how bad the Red Sea Alkalinity tests are, it is so hard to judge when it turns from baby blue to green without it going to yellow. Looking at the old test kids on youtube they turned a dark blue. Why did they change this?!?!?

I purchased some Seachem PhosGuard and it's been in there for 3 days now. I had only placed 1/2 cup and seems to have lowered it a little. I am now going to remove the current PhosGuard and replacing it with new PhosGuard as per instructions. After watching videos it does seem like GFO are a better option, although I was not able to get some. I will seek other LFS that stock them. Any feedback regarding PhosGuard?

NS Mike D

In the arena.
View Badges
Dec 19, 2017
Reaction score
Huntington. NY
lol. Yes Red Sea did change their ALk test kit for just that reason, so you stop at the beginning of the change.

re Phos Guard. read Randys post in this thread, it's Aluminum Oxide and removes both PO4 and Silica. Key here is to not leave it (or GFO) in the tank too long as it may leach thing back into the tank

as for silica, that's what diatom need. ideally you should test for silica before taking action. I am not sure the negative effects of removing silica but I do think some is needed.

When you feed your fish do you feel like your feeding the algae as well?

  • Yes I feel I'm feeding too much

    Votes: 111 30.2%
  • Yes but not much

    Votes: 142 38.7%
  • No

    Votes: 105 28.6%
  • Other (please explain)

    Votes: 9 2.5%

Online statistics

Members online
Guests online
Total visitors