Does tds measure phosphate?

[Txboi]

Just as the title says does tds measure phosphate the reason I ask is my to/ di water has 0 tds but when I test it it shows phosphate my unit has a inline one and I have a handheld when the water leaves the or membrane it says that there is 2 ppm tds and when the water leaves the di resin my handheld says there is 0 tds should I trust my tds meters or the test by the way the phosphate test kit is seachem

Thanks in advance

[bertoni]

Yes, TDS will include phosphate, but the amount of phosphate in RO/DI water will be below the detection limit of any hobbyist TDS meter of which I'm aware. What is the phosphate level in the tap water, and what is the SeaChem kit reading?

[Txboi]

The ro/di water comes out to be ethier a little below 0.05 or a little above but whats weird is that the tap water is the same is that normal

[bertoni]

I suspect that the phosphate kit is having problems. Personally, I would ignore the result. 0.05 ppm might be close to the detection limit of the kit, even if it's working properly.

[Txboi]

Yeah but the test kit say that it's accurate blow 0.05 and my tank water comes out to be 0 the only reason I worry is I have cyano but then agein another guy on here told me that the cyano might be just a phase that my tank is going through since my tank is only 3 months old

[Txboi]

I guess I'm just a little frustrated since my phosphate levels have been testing zero since before the cyano showed up as well as I've been using phoslock

[bertoni]

I'm not sure what to believe, but even if the phosphate level for the RO/DI water is accurate, it's probably not the cause of the cyanobacteria. That's not much phosphate, unless the tank is getting very large water changes.

[Txboi]

Thanks bertoni I decided to take water up to my lfs to have it tested and there was phosphate in the water so I've decide to get new filter media

[bertoni]

It's interesting that the LFS detected phosphate, too.

[nynick]

TDS meters are typically quite reliable. Hobby phosphate kits are typically not. I would trust the TDS meter.

A lot of things could cause cyano issues other than your rodi water. Food, LR leaching, dead snail, too little nitrates, light quality .... just to mention a few.

[bertoni]

I tend to agree, but keep in mind that the level of phosphate in question is below the detection limit of most, if not all, hobbyist TDS meters.

[Txboi]

Yeah that's what the guy at the lfs said I have a question for u can cyanobacteria be brown and really stringy

[Txboi]

I'm just wondering because I'm worried its Dino's but it never produces air bubbles

[bertoni]

I don't really know. It could be dinoflagellates, even without the bubbles.

[Txboi]

heres a pic to help

[nynick]

Very small pic, hard to tell. Diatoms are brown and stringy and do not form bubbles. Easy to tell apart from Cyano and Dinos even without a pic, just look at your cuc.

If cleaners eat it, it is Diatoms.

If they do not eat it at all it is Cyano. Keep in mind that snails leave trails if going through it since it comes off in sheets.

If they eat very little or get sick/die after eating it is Dinos.


There are thousands of species of Cyano/Dinos and we can get a few of them in tanks. Color is not always a good indicator. Most Cyanos we get tend to look the same but in different colors. Dinos can be very different from each other, Ich is a dino for example.

[joelbegt]

I was under impression TDS meters measure ppm so to read 1ppm of TDS you would probably need .5 or higher phosphate to read 1 TDS on my meter. Just throwing out ideas...

[nynick]

I was under impression TDS meters measure ppm so to read 1ppm of TDS you would probably need .5 or higher phosphate to read 1 TDS on my meter. Just throwing out ideas...

That is if it removes everything but not phosphates. I am no expert on the workings of a RO/DI system but I would assume they do not have any specific problems with filtering out phosphates or they would be pretty useless for this hobby.

[joelbegt]

I agree its just an example if somehow it was just phosphates. IMO low phos is nothing to worry over.

[Txboi]

Definitely not diatoms cuc won't touch it snail seem fine but my amphipod population has gone down

[Txboi]

It also started to grow on the glass I don't know if that means anything plus it grows in high flow areas

[Txboi]

And the strings are thin like sheets and almost 3 inches long and again I don't know if it means anything

[nynick]

check this site

http://www.reefcleaners.org/index.php?option=com_content&view=article&id=54&Itemid=60

[Txboi]

Yeah I've seen the sight before thanks though I think that I'm going to email a pic to them and see what they think the guy at the lfs said it looked like cyanobacteria I just wish it where purple or red that way I could be sure what it was I just rather it be cyanobacteria than Dino's I've read that Dino's is really hard to get rid of

[nynick]

To grossly exagerate. Cyano behaves like the film on boiled milk and Dinos behave like oatmeal porrage when you siphon them out. If it comes off in sheets and looks fairly clean after siphoning it is probably Cyano. If it comes off in lumps but still has a fair bit attached to the rock is is probably Dinos. Cyano seems to be more attached to itself than the liverock. Dinos seems to be more attached to the liverock than itself.

This is true for most Cyanos we get in tanks and the most common Dino in the hobby. Then you have the other 8954 species of Dino..... some of them can swim. :)

[Txboi]

Ok sort of get what you say it really hasn't gotten on the to is there's a couple of place where it's gotten on the bottom edge of the rock but when i siphon it of he sand it seems to be a then layer of sand that its attached to almost like it holds it together very loosely I don't know if that what you were describing when u say Dino's or does cyanobacteria do that? By the way thank you nynick for all your help and information your really helping me further my knowledge

[nynick]

I saw that on the picture which is why I was guessing Diatoms. Either of them can lump up sand, it is just a matter of if it is holding on more to the sand than the rest of the algae. Cyano will form choking mats by holding onto itself and growing more horizontally. It can cover large areas very fast by growing outwards.

Dinos grow more up from a spot they are in and can grow just as fast but I have not seen it cover the same yardage as quickly.

Oh, and Cyano stinks. Most algae smell a little icky but Cyano really smells bad.

Again, are you absolutely sure it isn't Diatoms? Color is not a good indicator and if you do not have a CUC that likes to cruise the sand......

[Txboi]

Yeah I have a fighting conch and it won't touch the stuff and its slimy and definitely spreads out

[bertoni]

That sounds like cyanobacteria or dinoflagellates to me.

[Txboi]

Well what ever it is I will beat it it won't beat me