Still trying to reduce phosphates

[medcinmn]

For a few weeks I have been trying to get my phosphates down. I have a 34 gal RSM, am not overfeeding or overstocked. No skimmer. After 2x a week water changes I decided to try Rowaphos. I’m deciding between changing out all the rowaphos, trying more water changes and getting a media reactor. Rowaphos is in a media bag on an InTank rack in the back chamber. It has gone like this

3/21

Hanna testers

Nitrate 7.8

Phosphate .77

3/23

Water change 5 gallons

3/24

Nitrate 7

Phosphate 0.79

3/25

Nitrate 4.6

Phosphate .82

3/28

Nitrate 2.1

Phosphate .86

Found old broken bag Chemipure (I forgot it was in there)

5 gal water change

Added Rowaphos 4.5 tbsp

3/29

Nitrate 3.1

Phosphate .69

Removed all but 1 tbsp+- Rowaphos

3/30

Phosphate .68

3/31

Phosphate .7

Added 2 tbsp Rowaphos (total 3 tbsp now in)

4/1

Phosphate .75

Added 2 more tbsp Rowaphos (total 5 in now)

4/2

Nitrate 7.3

Phosphate .71

4/3

Phosphate .68

4/4

Phosphate .67

Added 1 tbsp Rowaphos 6 total now in

4/5

Phosphate .59

4/6

Phosphate .58

4/8

Phosphate .61
Nitrate 7.1

 

[medcinmn]

Incidentally, system is several year old and fish and corals look good. I know, I know, don’t chase numbers lol. Just trying to get my phosphates down as I am considering some SPS. Currently all Lps and softies.

 

[Dr_Orpheus]

Do you sift your sand at all when you do water changes, or have some good sand turnover with livestock? There could be some nice hidden pockets of nutrients in some places if there isn't a lot of sand turnover....or in your filtration which happened to me in my Evo recently. Just a big pile of detritus on the bottom in the back, as the middle chamber is filled with rock rubble. Couple days after vacuuming that out and the system kinda sparkled that much more. Was up for about a year before I touched that, will probably do it more often now.

Edit: I just saw your previous thread as well. This phosphate issue will take some time haha. As long as nothing looks bad, continue on your path to cleaning up the system. I do highly recommend carefully sifting a portion of your sand well during every water change, remembering where you left off and moving eventually everywhere around your tank after multiple changes. I would also make sure your carbon and gfo (or similar media) is up to date, and maybe changed a bit more often than whatever is recommended. Algae may or may not sprout up during this as well.

 

[rishma]

Going slow is a good thing. Bad things happen when you reduce phosphate quickly.

You might also consider the phosphate you’re adding via food. It’s common to notice dry foods have more phosphate than frozen.

You will have a lot of phosphate bound to the substrates so it will release to the water as you remove it, making the phosphate level in the water stay higher. You’ll get there. Rowa works.

Far better to use too little rowa than too much. I like the approach you are taking.