Phosphate levels not going down

[mdbrownarch]

Hello all,

I picked up a 55 gallon FOWLR tank off of craigslist 4 months back and since have converted it into a reef tank. My coral, inverts and fish are doing very well, but I can't seem to drop my phosphate levels no matter what I do. Maybe I need to be a bit more patient, but I don't know.

Since noticing the high phosphate levels I have added an additional powerhead, phosphate filter pads to my canister filter, and started using an RO (~3 months now). My salt doesn't contain any phosphates, I have had a protein skimmer since day one, and do weekly water changes. I am not entirely sure about my feeding schedule but it seems reasonable: pellets once a day for two days followed by a single small chunk of frozen mix (homemade with various shrimp, veggies and phytofeast) on the third day. Then I repeat.

The only oddity is that the previous tank owner had some really old light bulbs (CF 10,000k and Actinic Blue) that I just recently replaced out of concern for proper light wavelength.

Any ideas?

pH 8.3
Ammonia 0
Nitrate 0
kH 9.5
Cal 480
Phosphate 0.25

Thanks for you help in advance!

[bertoni]

To Reef Central

What kind of filter pads are you using? For most people, a GFO, like PhosBan, is a cost-effective approach. You might go through a lot of filter pads, if the level is that high. I'd get a second opinion on the kit, as well. You might try testing some RO/DI water, as one sanity test. It should be near zero, assuming the filter is working.

[mdbrownarch]

Thanks for the reply bertoni.

I am just using some HBH Aqua-Pure Phosphate filter pads at the recommendation of a store I frequent. I also forgot to mention that they also had me start doing daily/bi-daily doses of Reef BioFuel (bioavailable carbon source) to reduce the level.

I will give my RO/DI water a test and get back to you. I may have to give this PhosBan a try if all is good on that front.

[mdbrownarch]

Just checked my phosphate levels on my RO/DI and it is basically zero, so looks like I need to run out and get some Phosban.

Thanks again for the help!

[bertoni]

I am not sure what's in those pads, but I am not convinced that they'll work in a saltwater setup. It might be a resin-style pad, which definitely won't work in saltwater. If the phosphate is real, I'd suggest trying a GFO.

What kind of protein skimmer is in use?

[mdbrownarch]

Gotcha. I am using a Coralife Super Skimmer.

[DeepSeaBeauti]

First losse the canister filter, They hold excessive nutrients and cause high No3 and Po4.
Then invest in GFO, Can be a bit expensive from the LFS but well worth the money, and it works amazingly well.
If all else fails, Vodka!! It did wonders for my tank before i got the GFO.

[bertoni]

How much live rock is in the system, and how much food is going into the system? The schedule is fine, but the amount might be too much.

What kinds of media are in the canister filter? I agree that they can cause nitrate problems.

I had one of those skimmer, and it didn't work very well for me. You might want to upgrade at some point, although they might have improved the design. Mine wouldn't produce a stream of fine bubbles for very long. The bubbles got coarse fairly quickly, no matter how much I cleaned it.

[mdbrownarch]

@DeepSeaBeuti - Vodka? Really? Cool. As for the canister, I have already invested too much money into fixing up this used tank in the past few months, so it is going to have to wait.

@bertoni - Likely around 50-60lbs of live rock. Guessing on the canister since I bought it used and am new to this. The canister has (bottom to top): substrate (white rock), thick blue filter pad, ceramic rings, thin white filter pad, phosphate filter pad (guessing these are the white rock and rings). Should I have something else or in a different order?

Also, picked up some phosphate buffer and am on my second treatment. Phosphates have lowered since the first treatment.

[OwenInAZ]

Welcome, and good luck in fixing your problem

I'd have to agree with the above -- when you can afford it, ditch the canister filter and invest in a sump and a good return pump.

Ultimately, using chemicals to deal with the phosphate issues won't fix the problem. My money is on getting a sump with some macroalgae to take up the excess PO4.

And yes, you can take the "one for me, one for you" approach with vodka dosing At the top of this forum (I think) there are several stickies related to this approach.

[bertoni]

The amount of live rock might be a bit light for the number of fish, depending on what's in the system. I agree that growing and harvesting a macroalga might help a lot. The GFO (PhosBan and the like) approach should help, too.