PH High even with RO water

[Jscoggins]

Hi everyone...my very 1st post...here it goes...

On my 55gal..I have had it 12 yrs..started live plants 3 or so yrs ago..I have always had high Ph 8.2 or so and hard water.. a yr ago I bought a RO system and do evap rep. only with RO water and when I do p.w.c. I try to use half RO and half tap (for the minerals) the tap is 7.2 or so..have checked to see if it raises with air overnight and it doesn't...the plants look"not great' black all over them and I have a lot of algae growth...don't know what to do!!!

Question: Why is the PH so high and won't budge with ro water and the little co2 i have in it?

The other 2 tanks I have ph is just fine..if I add ro water on the changes it will make their ph drop like fire in a very unsafe range..so I know that stuff works, but why not in my 55 gal?

 

[aqua_chem]

Is it just RO or RODI? Regular filter changes?

You could have something in the tank that's leeching carbonates... This can be common with some sands and rocks.


pH and RODI by them selves isn't bad for plants and wont cause algae, pH especially so. If you're not adding fertilizer to the water to account for what you're removing, this might also be an issue. IMO, the vast majority of algae issues are caused by CO2/light issues or insufficient fertilizers.

 

[Xand3r]

Hi everyone...my very 1st post...here it goes...

On my 55gal..I have had it 12 yrs..started live plants 3 or so yrs ago..I have always had high Ph 8.2 or so and hard water.. a yr ago I bought a RO system and do evap rep. only with RO water and when I do p.w.c. I try to use half RO and half tap (for the minerals) the tap is 7.2 or so..have checked to see if it raises with air overnight and it doesn't...the plants look"not great' black all over them and I have a lot of algae growth...don't know what to do!!!

Question: Why is the PH so high and won't budge with ro water and the little co2 i have in it?

The other 2 tanks I have ph is just fine..if I add ro water on the changes it will make their ph drop like fire in a very unsafe range..so I know that stuff works, but why not in my 55 gal?

Try answering some of these questions so you can get the right answer

How much water do you change per week?
What is the pH of your tank?
Define little CO2
what kind of lights are you using and for how long
Do you use any ferts?

Think of R.O water as white paint and hard water as black paint. If you add any color to white paint it is going to change the original color pretty easy, but if you add the same amount of color to the black paint, it is going to make little or no difference at all. Or in other words, when you filter your tap water, you are just removing the minerals that make it hard so you can manipulate the pH or other factors. But if you dilute it with tap water you are pretty much wasting your time because the water is going to mix and most likely conserve a high ph, that is the main reason why most people adds their own minerals or buffers instead of mixing half and half.

I don't know what you are trying to grow n your tank but I would try to use only tap water and see if you get better results, most plants will adapt to the pH if everything else is right (nutrients/light). Also the algae growth is most likely due to a nutrient imbalance and/or extended photoperiods (10+ hrs of light). I would also read a little about RO water and water chemistry (kh, gh, ph, etc...)

 

[aqua_chem]

Think of R.O water as white paint and hard water as black paint. If you add any color to white paint it is going to change the original color pretty easy, but if you add the same amount of color to the black paint, it is going to make little or no difference at all. Or in other words, when you filter your tap water, you are just removing the minerals that make it hard so you can manipulate the pH or other factors. But if you dilute it with tap water you are pretty much wasting your time because the water is going to mix and most likely conserve a high ph, that is the main reason why most people adds their own minerals or buffers instead of mixing half and half.

Why would you mix your own minerals and buffers when you already have minerals and buffers present in the water?

 

[Xand3r]

Why would you mix your own minerals and buffers when you already have minerals and buffers present in the water?

To be honest I think that it is easier to add x number of spoons or ml of a commercial buffer to x gallons of water rather than start mixing and measuring the pH. Sure once you have done it the first couple of times you know exactly how many gallons or liters you need of each, but if you are using RO is because you want to achieve specific parameters. In my opinion it is more consistent. And I'm sorry if it sounded like I would mix my own amounts of trace minerals, Zn, Mo, Mg, Mn, etc, that's not what I meant.
However, my point was that if you don't have anything extremely delicate in your tank RO water is a waste of time.

 

[aqua_chem]

To be honest I think that it is easier to add x number of spoons or ml of a commercial buffer to x gallons of water rather than start mixing and measuring the pH. Sure once you have done it the first couple of times you know exactly how many gallons or liters you need of each, but if you are using RO is because you want to achieve specific parameters. In my opinion it is more consistent. And I'm sorry if it sounded like I would mix my own amounts of trace minerals, Zn, Mo, Mg, Mn, etc, that's not what I meant.
However, my point was that if you don't have anything extremely delicate in your tank RO water is a waste of time.

I'm just going to emphasize this while I'm at it. This is an important point that should have been mentioned earlier.

 

[Jscoggins]

Don't forget to read my profile..I did fill it out best as possable....some questions will be answered there..

It is RODI water, and yes I change my filters once a month.

The water changes 10% I do every 3-4 wks.. I add about 5 gal a week of rodi water for evap.

So maybe I don't have enough CO2 going?!?! And I haven't added any ferts to my substrate since inital set-up (3 or so yrs ago)...I do add ferts to the water...After reading alot here, I did go out last Thursday and get some root tabs, and put them by the plants..So yes, I have done bad in that area...time just gets away from ya and before you know it, it has been 3 yrs....lol...
Would that cause the black algae on the plants though, or is that the light and CO2 problem?

I'm not going to have any fancy plants, I just want to grow some plants!!! And them look like my flowers out in the garden, all happy and stuff..and right now they are not that!!!
I know I can do better!!!

Well, I read that not enough co2 for the plants would cause them to feed off the minerals in your tank and then you have a lack of minerals which result in a higher ph..has anyone read or heard of that?

So you think RoDi water is a bad idea and I should just do tap? If the above statement is true I have a major lack of co2 in my tank!!!
I have read that to much light and not enough co2 would result in algae too...I'm thinking I have more than one problem...ohhh boy....

You know I have never tested the aquarium rocks to see if they would cause the ph increase...I will put one in an 5 gal. bucket and fill it with water and see if it causes a ph rise..would you add air to do that?

Thank you everyone for your help...

 

[BBradbury]

Your pH Question

Hi everyone...my very 1st post...here it goes...

On my 55gal..I have had it 12 yrs..started live plants 3 or so yrs ago..I have always had high Ph 8.2 or so and hard water.. a yr ago I bought a RO system and do evap rep. only with RO water and when I do p.w.c. I try to use half RO and half tap (for the minerals) the tap is 7.2 or so..have checked to see if it raises with air overnight and it doesn't...the plants look"not great' black all over them and I have a lot of algae growth...don't know what to do!!!

Question: Why is the PH so high and won't budge with ro water and the little co2 i have in it?

The other 2 tanks I have ph is just fine..if I add ro water on the changes it will make their ph drop like fire in a very unsafe range..so I know that stuff works, but why not in my 55 gal?

Hello J...

Your question is interesting and I'm not sure I can help. But, here's what I've learned about reverse osmosis water: In short, it isn't a good idea to use it. RO water contains nothing to keep the acidity or alkalinity of the tank water stable, so can allow sudden changes.

Unless you keep and raise rare species of tropical fish, a pH of 8.2 is quite tolerable. The vast number of tropical fish species will adapt to the vast majority of public water supplies.

I don't know the particulars of the kind of fish you keep, but I don't see how you could go wrong with changing and replacing half the water in the tank every week or so with just treated tap water and let the fish and plants do what they've done since the fish keeping hobby started and that's adapt. Your fish will thrive in the pure water conditions and your plants will appreciate the high mineral levels.

I think at times, in an effort to make our tank better, we lose track of the basics.

Helpful or not, that's what I can tell you.

B

 

[CorallineAlgae]

If you're mixing 1/2 tap and 1/2 RO water you're fine. You'll get all the buffers you need, especially since you have hard water from the tap. You don't have to do it in most tanks but it won't hurt your system. I suspect it's either your substrate or perhaps some other calcarious rock in your tank causing your ph to stay so high. I think aqua_chem asked you about this. What type of gravel or sand do you have? If you want to test it a common way is to take some of your gravel or stone out and pour a spoonful of muriatic acid on it (people use this inexpensive acid in swimming pools). If it fizzes it's got calcium in it. That's the method I've used. Still, do you know what type of gravel is in this tank? Is it different from the stuff in your other tanks?

 

[Jscoggins]

I have regular aquarium gravel that you buy at the pet store or walmart. The same with the rocks, I got them at petsmart..I have had the same 3 rocks and the same substrate for 12 yrs..If it was something in them, wouldn't it have came out by now?

 

[CorallineAlgae]

Just brown pea gravel? If it's white or grey and you got it 12 years ago it could be dolomite, if it's brown pea gravel it should be fine. Rocks sold that long ago could be just about anything. If they're calcareous they would buffer your ph until they completely dissolved.

 

[Jscoggins]

The gravel is the small, white and blue, you know the mixed 10 lbs. bags you see...I will read up on how to post a picture and put one of my aquarium on there.. Thank you for your help!!!

Over the weekend I did a very large w/c 75% with just tap water and added the 2 - 2 ltr. bottles of dyi co2 and my ph has went down as of just couple of min ago to 7.8..the lowest ever...Would you do another w/c in a week and would you do another large one? But how large?? Should this w/c be a weekly thing and maybe my ph will go down and stay???

 

[Jscoggins]

This is my tank...All the black that you see on the bottom portion of the plants is black hair algae...I think..but they have new growth on top..go figure

 

[CorallineAlgae]

Your pictures make your high PH issue very clear. Those rocks you have look like they are made of solid lime. They, at least by what I can see from your pictures, look like rocks that would be at home in an African ciclid or even a saltwater tank. Beautiful as they are, you won't be able to have a soft water environment with even one such rock in your tank. Consider getting a little muriatic acid from a home center and doing a test on your stone (and the gravel just to rule it out). If you have a friend with a pool you may even be able to use a spoonful of his.

 

[Jscoggins]

I bought all my decor. at petsmart 12 yrs ago. You really think petsmart would sell pure lime rocks to go in an aquarium, and mark it as such, just as "decor"..??? Just asking ???

But I will do the test just to rule it out...

 

[Scott F]

I change 10% a week, if not a little more in my 10gal, and 50% ( at least ) once a month in both my 10 and 40 gal.

PH from our water has always ran between 7.6 and 7.8.

BTW...Cool looking tank !

 

[CorallineAlgae]

I bought all my decor. at petsmart 12 yrs ago. You really think petsmart would sell pure lime rocks to go in an aquarium, and mark it as such, just as "decor"..??? Just asking ???

But I will do the test just to rule it out...

Sure they would. It's great rock for certain kinds of tanks. That rock should've been expensive. If it turns out to be incompatible with a planted tank that doesn't mean it isn't good for a different kind of tank (African). It's no shock that they wouldn't mark it as something for a specific use. They sell plants every day for planted tanks that cannot survive submerged under water. Knowledge is in small supply in most petsmarts.

 

[Jscoggins]

You do have a very good point...I don't know why I didn't think of it in that way...You would think they "Mfg" would mark it some how....I'll post what I find out...Thanks!!!!