View Full Version : Phosphates too high

02/22/2006, 12:37 PM
Sorry I could not use the search, seems server is too busy.

I have a JBJ NC24 with 20# live sand and 25# live rock.
parameters are all fine except phosphate too high.. That's because stupid me used tap water (with conditioner) to fill it up. That means if I let the lights on too long, a brown layer gets on the LR and part of the sand also.

Filtration is carbon and foam filters, that's it.

I changed twice 5 Gals of water (I used water from the grocery store, which states it's RO) but it's still high on the test i tested that water alone for phosphate and the solution doesn't stay completly clear so i guess it's a little over 0.

Now what are my options?

Am I better with chemicals (which ones?) and frequent (how frequent?) water changes (how manu gallons??)

Or simply make a HUGE water change almost restarting the tank from scratch (let's say 20gallons at once)...


p.s. You might have read about it on nano-reef (got some pictures there too) but i don't have access to it from work and this community seems a lot more active so I'm guessing I can get more opinions here.

02/22/2006, 01:11 PM
I had an issue with phosphates and recently put a Phosban Reactor in my sump and put Rowaphos in it. After three weeks...the phosphates dropped from 1.0 to 0.1 on my Seachem test.

02/22/2006, 02:00 PM
I recently responded to a separate thread discussing a cyano issue ... since cyano is almost always associated with phosphates I copied my response in the hope it may help.

"If you have a major cyano problem then you have a phosphate issue. Your focus should be on trying to limit importing phosphates into the tank while attempting to remove/export the maximum amt. of phosphates.

Prime sources of phosphate in a tank are tap water and food. If your using tap water you need to spend a $100 and purchase a good RO/DI device on EBay. All food has phosphates .. some food like "flake" are loaded with phosphate. If your using flake food then switch to frozen. If your using frozen food then make sure you thaw/rinse before feeding. Of course cutting back on feeding will also limit phosphates regardless of what your feeding.

Best methods for exporting phosphates include .. water changes (using phosphate free water), wet skimming, daily manual removal of phosphate laden cyano, phosphate binders (phosban etc), and kalkwasser may cause limited amts. of phosphate to precipitate out of the water column.

Other procedures that will help include .. maximizing water flow (keeps the crud that will release phosphates suspended within the water column so it can be skimmed or removed by filtration) as well as daily rinsing of any filter media until this problem is behind you.

Some people will resort to chemi clean and some will resort to use of antibiotics ... not something I would recommend but many have positive results ... if you go this route make sure you do your homework."

Good luck .. Hope this helps.

02/22/2006, 02:08 PM
wow thanks for those replies.

Since my tank is "new" I guess the most radical/fast would be to make a major/complete water change with RO water. Then I'll monitor.

I guess phosban and other alternatives are better once you tank is populated / settled so you can reduce it.

Thanks again!


02/22/2006, 02:52 PM
Also, you may want to test the water you are getting from the store, they are not allows ontop of changing the filters.

02/22/2006, 04:30 PM
What parameters should I test?

I tested phosphate and to my huge disappointment it wasn't clear but lightly blue (hard to give a # but I'd guess 0.25).
Should i test TDS? (if yes I need to buy a TDS meter)

I'm thinking of buying that 100$ (plus 32$ shipping) unit on eBay for RO.. bu I would not have it fast enough for that water change (I plan to start preparing the water this evening - already 5gal ready)


02/22/2006, 06:16 PM
Reading phosphate levels within the show tank is a difficult and probably impossible task .... the std phosphate test kit can only register inorganic phosphates which are quickly consumed/absorbed by phyto/bacteria/cyano/algae etc so even a phosphate laden tank often reads zero phosphates. Kinda of a catch 22 thing ... a phosphate reading tells you you definitely have a problem .. but no phosphate reading combined with cyano or other obvious phosphate loving algae generally means you still have a phosphate problem. In the long run the best use of a phosphate test kit is to measure the phosphate level of the water your putting into the tank.

As far as Ebay RO/DI devices .. you can pick one up for about $100 (delivered) anything more usually means your paying for a holding tank which is not required for Reefing.

Hope this helps.

02/22/2006, 06:57 PM
this a good thing to know.

I'm doing my huge water change, I guess it's the best solution, if sometime the levels gets back high and I have stuff in it probably the chemical solutions will be better... but now it's really a breeze to just switch 95% of water (almost starting over again in fact)

can you point me to a 100$ delivered filter on ebay? The one I saw were with a 4Gal tank and 100$ plus shipping (32$ ouch)


same price but one with tank one without..


02/22/2006, 06:57 PM
In this situation, I'd do a series of 25% changes to reduce the phosphate level. That should reduce stress on the live rock, etc.

An RO-DI unit would be a good investment, IMO. The airwaterice.com models get some good reviews. I'd ask them to switch the RO membrane to a 75 gpd unit, since those membranes do a better job of cleaning the water.

02/22/2006, 08:27 PM
Just do a search of Ebay .. prices vary from month to month but I have no doubt that if you do a std Ebay search using reverse osmosis you will see a number of 5/6 stage units selling for $60-70 which should equate to a delivered cost of about $100. Aquasafe used to sell in this $ range but I think they now stick on holding tank and have raised their prices about $20 ... heres an inexpensive unit that should work - might find better with some searching.


I have not used this particular unit .. but the people I know who have used it say it works fine .. only complaint is the seller is from taiwan and doesn't speak/write english that well.

02/22/2006, 09:17 PM
I wondered if a high phosphate level (not extreme, but high) would stress any of the livestock in a reef, or do phosphates only serve as a source of nutrition for algaes. Maybe someone can answer that. The other thing I've wondered about, is that IF there are elevated phosphates and nitrates in a reef and the phosphates are brought down to negligible levels, will the nitrates begin to drop, due to macro-algae in a refugium resorting to nitrates since there are less or no phosphates available.

02/22/2006, 09:25 PM
I bought and installed some rowaphos, I've been suggested not to do a complete water change just to not have to cycle again.

I will still will do 5 gallons changes as often as possible (maybe each 3-4 days) and I guess htis should help it.

Thanks for your replies


02/23/2006, 12:36 AM
Phosphate can reduce coral growth by inhibiting calcification, and can also stimulate zooxanthellate growth, apparently to the point of stress on the coral.