PH Issues and plant growth

[MoeCanada]

I ran into the problem with my system. My system is in it's 5th week and i started noticing that my tomato plant leaves were turning really yellow, so i added chelated iron thinking it will cure the problem but it got verse in the next two days so i went to pet'smart ( iam in canada) and got the test kit. My PH was 5.3. My fish seemed to be doing fine, all other plants are growing but tomatoes are just becoming more and more yellow. It's a small system with 70 gallon fish tank and two grow beds. There are other plants like pepper, beans,peas,cucumber,eggplant and basil. The rest seems to be doing ok. The tomatoes are the one most effected. Beans started flowering but the pods seem to be very small and have a brown thick line on one side. I have clay pebbels (hydroton) in the beds. The beds flood for 5 mins and then drain in 45 seconds. The system is in my basement with flourescent lights as it's very cold here outside in canada ( -5 c) already but temprature in the basement has been maintained at 20C. I have about 70 fingerlings in the tank. Could somebody please advise as to what i could do to cure the problem ? and does that low of a PH effect plant and fish really bad? . Thanks for your suggestions and feedback

[RupertofOZ]

I replied to your other post... in the other pH thread...

[Wendy in BC]

Hi Moe,

That pH is shockingly low, you'll have a very hard time establishing a bacterial colony.

What is the pH of your source water? Presuming you use tap water, do you do anything to it (other that let it sit overnight to remove chlorine), before you top up your fish tank?

Do you have a test kit, so that you can test for ammonia, nitrites and nitrates, in addition to pH? If you do what are the other reading? If not, I suggest you get one.

How much growbed volume do you have. You mentioned hydroton, is that the only media in the beds?

What are your growbeds, and Fish tank constructed with?

I know John mentioned in the other post that 70 fingerlings were alot, but until recently I stocked far denser that that, and it's not likely the source of the low pH (yet). What type of fish are they and roughly how big?

Pics could prove helpful.

Wendy

[Erich]

agree with the above...

Get the PH up - yesterday - then work on other stuff

[RupertofOZ]

Actually just re-read the post....

5th week... pH 5.3... basement temp 20... so fish tank probably 15-18....

Doubtful you've fully cycled yet... although you might have...

Need the rest of your reading... but yep... bring your pH back... it might have crashed a "young" bacterial colony... although I'd expect to see elevated nitrites at least... if not an ammonia spike as well...

[RupertofOZ]

I know John mentioned in the other post that 70 fingerlings were alot, but until recently I stocked far denser that that, and it's not likely the source of the low pH (yet).

70 fish in 70 galls (250L).... is a LOT of fish... and could well be the cause of falling pH ... if the system were cycled... and nitrification working properly...

I really need the ammonia and nitrite readings...

[Wendy in BC]

Forgot to ask Moe:

How are you cycling your system?

[MoeCanada]

Hi All,

Thank you for your feedback. Here are the complete details with some pictures.
The PH of the tap water is 7.2 . I put top fin water conditioner to remove chlorine which says at the back " reduces chlorine, chloramine and heavy metals. Replenishes necessary electrolytes to reduce stress.

I did a test for everything results as follows:
ph: 5.3
Ammonia: 0.5
Nitrite:: 0.8
Nitrate: 20

One grow bed is 4'x1'x6" and the other one is 3'x1'x8". The fish tank is 70 gallons. Both grow beds are made of plastic. One i bought from Hydroponic store and other from walmart. Fish tank plastic tub from canadian tire. Hydroton is the only media in both beds.

When i started i just filled the tank with water and set the grow beds up. Let the whole system run for 3 days. Then added the seedlings from my seedling tray. Bought the fish the fifth day and originally had 71 but one died but the other 70 seems to be surviving fine.

Iam posting some pics here as well. Should i use hydrated lime to bring the ph up or crushed eggs shells?

You will notice the new growth is really yellow in the pictures.

[Yabbies4me]

"Should i use hydrated lime to bring the ph up or crushed eggs shells?"

Eggs shells would be too slow and you would need heaps, just add lime, I think Rupert covered it's application for you on another thread. You could still add egg shells to help harden your water and buffer pH, but it it's a slow leach, not an instant result.

Of more concern than nutrient deficiencies in your plants at 5.3 pH, is the effect low pH will have on fish slime coat production and your beneficial bacteria colonies.

Regards, Yabbies.

[Erich]

agree with Yabbies (again )

You need to get the PH up to say mid 6's asap