testing RO water

[DPdsny]

I'm trying to find the cause of a hair algae problem. I'm getting a phosphate reading of 0.2 using a SeaTesT test kit. I have done a few water changes but it does not seem to be getting any better, I tested the water coming out of my RO/DI unit and got a 0 reading. so I cut back on the feeding, that did not help. I used a phosphate sponge, that did not help very much. then it hit me...am I supposed to be using a fresh water phosphate test kit on the RO unit.

 

[essmaker]

I don't think it matters for phosphate, but I'm not sure.

 

[DPdsny]

I think your right I have been looking around and I don't see any freshwater only test kits. well.... there goes my hopes of a quick fix on this phosphate problem

 

[Witfull]

try a salifert test kit,, thay cost a bit more but are excellent.

 

[ReefLady]

Mix some of the RO with salt mix to the appropriate specific gravity, then test it.

 

[wooddood]

let us know dp.

 

[RanRoc]

I agree with Travis...Phosphate could be in salt mix.
-RY

 

[DPdsny]

im making a small salt mix now. i will test it and let you know.

 

[swissgaurd]

DP how old is your R/O unit
have you replaced the filters
R/O units are usually checked for TDS
I replace my filters every six months

after u replace filters and u get a high TDS then your membrane needs replacing.

if you have a local water purification store sometimes they will test your TDS for ya.

vic

 

[DPdsny]

TDS?? what is that.
my ro/di is still pretty new less then 6 months

 

[swissgaurd]

total dissolved solids

 

[DPdsny]

well I tested a small batch of salt water and got a 0 reading. I don't know what else to look for.

 

[RanRoc]

I think someone mentioned this before, but did you try a new test kit? This may not identify the source, but may help reduce the Phosphate a bit: Poly-Filter Pads. Keep us informed.
-RY

 

[jks1]

DP, what kind of substrate do you have in the tank?

 

[DPdsny]

its 2-3 inch of southdown sand and 25 lb of live sand

 

[DPdsny]

ranroc, I got a new test kit to day, I tested my tap water my ro water and my ro/di water just to see if it would show any different type of reading...and it did so I know the test kit is good.

 

[Mebigloser]

I am not sure how this board feels about using certain chemicals or things in the tanks, but I had a terrible problem also with Phosphates. Went to R/O water, cut down on feeding, check the R/O water before and after adding salt.... was lost..I recently used a product from Seachem called Phosguard (Phosphates/Silicate remover) and had excellent results. Hair algae disappered and sand cleared. I can post pictures if needed.

 

[ReefLady]

OK DP, you've found the answer to your original question.

The phosphates are not coming from your RO water, and they're not coming from your salt mix, or you would have measured some PO4 in the freshly-mixed water.

This means you need to look inside your system... feeding habits, protein skimming, mechanical filtration... tell us all about your system and hopefully we can pinpoint your phosphate source but it ain't the RO water.

Travis

 

[DPdsny]

ok this is what I got. 75 gl, 2- 3 inch sand bed, 70 lb live rock(added in July), Eheim pro wetdry canister filter, Remora hang on skimmer.one yellow tang, 1 blue damsel, 2 hermit crabs, handful of snails. I feed once a day at night 5 times a week, I switch between frozen foods, flake, and dry seaweed. when I feed frozen I thaw it out and rinse under RO water.
I would like to stay away from using any type of chemicals to fix this problem but it looks like I'm running out of options
thanks for any info

 

[ReefLady]

I'd unhook the canister filter, my guess would be that's your source. With 70lb of LR and a DSB, it's redundant filtration IMO- you've got plenty of biological filtration without it, and don't risk the negative effects of wet/dry filtration- particles trapped in the water column rotting, and nitrates more specifically.

Travis