PH

[Sarah99701]

I have a 55 gallon aquarium with live rock stacked to the top. It's been running for about a year but no fish yet just a few snails, crabs and a sea urchin and a brittle sea star. Specific gravity stable at 1.024. I have been having an algae problem and a PH problem. So I purchased a RO/DI unit. I decided to test the RO water (no salt added) to see what the PH was and it was still around 7.8 (I don't have a meter). I thought that it would be higher. I had planned on doing weekly water changes with changing the water out gradually to all RO water. I have a protein skimmer and a canister filter running. So my questions are
1. What is the PH of just RO/DI water prior to adding the salt?
2. Would the salt raise the PH when I add it? (I needed to just add some freshwater because of evaporation)
3. Can you have to many bristle worms? When I look at my tank I can always count at least 10 without really looking
Thanks Sarah

 

[Ingy]

Sarah, first off, what are you using for tests? a pH of 7.8 is quite high for tap water, and even higher for RO water. Pure water should be 7, normal tap water is normally slightly caustic at around 7.2, but it varies based on local water supply and treatment. But 7.8 is way too high IMO. Baking soda added to tap water will normally peak out around 7.8 due to the carbonate/bi-carbonate balance, so tap water shouldn't be that high.
Yes, adding aquarium salt to water should further raise pH. Most aquarium salts are balanced in the 8.3-8.4 range.
You bristle worm population will balance out based on food supply. The more food that ends up in the rocks the more bristle worms you'll get.

 

[Sarah99701]

I thought the RO/DI was supposed to help raise the PH? RO/DI is actually lower in PH then tap water? What is IMO? Raising PH is complicated I guess. So when I add the salt to the water it will raise the PH in the RO/DI water MORE then if I added it to just tap water because the tap water has to many other things in it that counter act the salt/elements?
I will add the salt and retest the PH. Happy to hear my bristle worms are fine.
Thanks Sarah

 

[Sarah99701]

Forgot to add, I am using the PH test where you put 5 drops of the testing agent in 5cc of water and compare the color.

 

[Ingy]

First, pure water has a pH of close to 7.0. It should not raise pH unless your tap water is below 7.0. So a RO/DI unit may raise pH, but only to 7.0. Adding salt should raise pH no matter what your adding it to, but yes, the chemical composition may have a minor effect on how much it goes up. The closer you are to the salt's target pH (8.3ish) tho, the less it will go up.
7.8 is lowish, but not terrible.

Terms
IMO - In My Opinion
pH - power of Hydrogen (what we are talking about)
PH - Power Head. The circulation pumps we add to marine aquariums.

 

[Sarah99701]

PH rising

Added the salt to some of my RO/DI water and the PH was 8.2 YEAH
Can't wait till the whole tank is up to 8.2
Thinking about a UV sterilizer to help with the algae problem also.
Any thoughts?

 

[Ingy]

Algae is caused by excess nurtients. Wee little plants. UV sterilizer won't help at all because algae attaches to a surface and grows. It doesn't float around the tank like some bacteria do.
Having no fish, I'm wondering if your feeding the CUC in your tank?
Also, what type of filtration system do you have? HOB (hang on back) filter, Power filter, sump?
Any nutrients you put in the tank (which will be reduced because of the new RO/DI system you have), including any food, eventually has to come out. Either cleaned with a filter, skimmed with a skimmer, converted (to nitrogen) with bacteria or chemically via resins.